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What files can I safely delete in Windows Explorer?

by Lee Koo (ADMIN) CNET staff/forum admin / July 20, 2007 3:08 AM PDT

First, thank you for this great newsletter and its helpful members. I was wondering about going through Windows Explorer and deleting unneeded files. In the past I've done this with some unfortunate results, creating panic and migraines. So now I just look at the extensions and figure I'll leave them alone, except many new files are piling up. What is safe to remove and what isn't? For example, recently I found a folder "minidump" and extensions .dmp. Is there a list out there so I know what file types are safe to remove? Others might want to be guided to removing and lightening up their computers, too. Is it worth messing with? Any advice on the best practices of removing unnecessary files would be appreciated.

--Submitted by Tom D.

Answer voted most helpful by our members

Safe to delete?

Firstly, what NOT to delete:

Any file with the following extensions are to be kept: EXE, DLL, DRV, VXD, COM, INI, 386, CPL, INF, OCX, SYS and some others. There is an exception: INSTALLATION files. Once the program has been installed, the installer may be deleted if you want.

TTF, TTC, FON and OTF are fonts files and normally in the font folder. Those that are elsewhere are NOT available, delete them OR place them in the font folder.

HLP and CHM are help files. Your call! If you no longer need some help, you can remove them, but it's good to keep those that you use the less, as they are those you'll most likely need to consult if you happens to use the corresponding application or feature. Also, good to keep those of programs that you rarely use.

ICO are icons. ICL are icons library. Most can be removed, at worst, some files will receive the "default" icon.

Now, files that are SAFE to delete:

ALL TMP (TeMPorary, some are in use and thus undeletable), DMP (DuMP files, may be useful for some debugging, IF you are an expert), the content of any "temp" and "tmp" folder.
The content of the "temporary Internet Files".
Don't forget to periodically empty your trash can. ALWAYS do it before defragmenting as it release some working place on the drive and reduce the number of files to optimize.

Any BAT files? Explicitly open them in a text editor, like notepad. If they don't open, or are over 64K in size, DELETE them as they are NOT proper BATch files! BAT files are text command script files, editable and viewable in notepad, that contains automated instructions for some process. By definition, they MUST be less than 64K. INI files have the same mandatory size limitation.

Open those LOG files in a text editor, if they don't appears to be installation logs, you can delete them. Installation logs contain LOTS of mentions of copying and moving files, full files paths, usually the name of some program, date of the install and some other information. You must absolutely NEED them if you ever want to uninstall the related program for any reason.

The following can always be suppressed: DIZ, 1ST, ME,CHK, NFO.

After a crash, you may have one or many "foundxxx", where the "xxx" is a 3 digit number, folders with one or more files. Those are "recovered" file fragments. You can safely suppress those folders, as the content is almost 100% pure junk.

Sift trough your images and other medias, you can delete any that you don't wish to keep. Any file that you created or downloaded and no longer need or want can be suppressed.
If you never use a screen saver, you can delete the corresponding SCR, and possibly INI, file. Some screen savers also use an EXE file, it have the same name as the SCR. If you deleted the SCR and maybe INI, you can remove that EXE.

Any ZIP or other archives? Take a look at the content, if you find some that you don't want to keep, or don't even remember why you have it... give it a one way ticket to the trash can.

Open the "Add/remove programs" and look at installed applications that you no longer use. Uninstall them. Don't touch those that looks like they are associated with your installed hardware and peripherals, even if you don't think they are used: they probably ARE used in the background.

Finally, for ANY file that you are not sure about but think that you may want to delete: Make a copy, possibly compressed, that you keep in a safe location BEFORE you delete. That way, if the file comes up as really needed, you can restore it easily. It's a good idea to include in the archive some text file that say why those files where archived, their original location and any other information you may think about.
Be carefully if you navigate the windows folder and any of it's sub-folders. It's the CORE of your system! While there are files there that can be removed, like images and some SCR, most are essential.

You should also be careful when navigating the Program Files, as it contains most of your installed applications.

--Submitted by Alain Martel1

If you have additional advice for Tom, let's hear them! Click on the "Reply" link to post. Please be detailed as possible in your answer. Thanks!
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Cleaning up junk files
by davialex3232 / July 20, 2007 11:53 AM PDT

I use system suite 7 or urinstaller both clean up junk files windows Xp professional and home edition leave plenty around

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How to know what you can remove ....
by Watzman / July 20, 2007 12:37 PM PDT

There is no magic answer to this, and the safe answer is that you don't remove something if you don't know what it is. But when you run across something that you are unsure about, either a folder name that you didn't create or files with a "filetype" that you don't recognize, Google is your friend. A Google search can often tell you what the item is, enabling you to perhaps make an informed decision about retention vs. erasure. But the safe answer comes back to "if you don't know what it is, don't erase it".

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How does one find a AV installer in 90048 90069 90046
by jesskalinowsky / July 20, 2007 1:50 PM PDT

How does one find a AV installer in 90048 90069 90046

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How does one find a AV installer in 90048 90069 90046
by aliensquirl / July 20, 2007 2:26 PM PDT

jesskalinowsky, you're a little off the thread subject there, but... first, does your AV mean 'antivirus'... and what the heck is 90048 90069 90046?

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(NT) Well, they are Los Angeles Zip codes ...
by drpruner / July 30, 2007 9:40 AM PDT
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My answer for Tom D.
by aliensquirl / July 20, 2007 2:22 PM PDT

Tom, I think the average computer user is not familiar enough with the nitty-gritty of computer files to randomly delete files from Windows Explorer.

When an application is installed it can put files in different folders and a single file in a folder may be crucial to the operation of an application so it's hard to tell what should be kept.

The best way IMO is to uninstall an unwanted application through the Control Panel or the application's uninstaller. Sometimes this additionally requires manually deleting files from Windows Explorer, but you will be given the file names so you'll know exactly what to delete.

Good luck.

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Use Disk Cleanup, System Restore, Backup and AVIRA Undelete
by flashmx2004 / July 20, 2007 5:20 PM PDT

First, use Disk Cleanup. This is one Windows utlity that really works. Clean Temporary Internet Files, Recycle Bin, Temporary Files,Thumbnails [Vista], and all others. But If you do not like installing ActiveX and Java applets, leave only Downloaded Program Files and Hibernation File Cleaner empty, but clear all the others. Use System Restore about once a week, or before you start a cleaning spree. Should you delete a program or registry entry, you can restore it. Backup frequently so that you do not accidentally delete files that you want. Finally, if you have deleted a file and have not backed it up, use the free Avira Undelete to restore your file back from infinity.

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A quick easy answer
by ldsaint / July 20, 2007 5:22 PM PDT

This one is really easy to answer, If you are not sure what you are doing get a tried and test program to do it for you. Innovative solutions have a product called advanced uninstaller pro. It has tons of tools to safely clean up your system and you get a fully working version for 15 days, which is enough for a good clean up, but I have found it so useful I bought it.

I have a friend that goes trawling through his system looking for things to delete, and I have spent hours repairing it and reformatted his system twice as a result. You really dont need to do this kind of thing with xp if you sort your settings out to delete internet files and use the disk tools, the rest of the files are usually of no detriment to a system. Incidently *.tmp ie. temporary files and dump files are usually ok to get rid of. I used to do it manually before advanced uninstaller pro, now I just cant be bothered as its so quick and easy.

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A non-issue
by dg27 / July 27, 2007 8:46 PM PDT
In reply to: A quick easy answer

Although there has been some interesting information posted in the replies, everyone seems to be missing one hugs factor: In terms of the space "unnecessary" files are taking up being "huge," what is "huge" these days?

My recommendation is to find one of the many useful "cleanup" utilities to rid your system of junk and leave it at that. Read the reviews to determine which utilities are the most effective.

With hard drive space running @ 30 to 50 cents per GB if you know where to shop online, manually going thru the Windows or program folders is ridiculous.

Life is way too short for this.

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A non-issue? I respectfully disagree.
by ironjawz61 / July 27, 2007 10:42 PM PDT
In reply to: A non-issue

Sure... With the cost of storage being so inexspensive, get a huge hard drive and a program to do the cleaning for you, If you can afford it. But, believe it or not, there are many people in this world who cannot spare the exspense of even a few dollars for a larger drive. Maybe their only option at the time is to delete as many unneeded files as they can safely delete just to keep the system going. I was one of these people about 9 years ago. I had no choice but to manually search and delete. A side affect of having to do that was that I learned alot about my system and how to maintain, modify and repair my computers myself.
So what may be a non-issue to you may very well be an important issue to someone else.

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by break123 / August 7, 2007 7:36 AM PDT

thanks, you have spoken for many!

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More advice
by skycatcher / July 20, 2007 6:53 PM PDT

Some good answers above - especially the 'Google it' one, find out what it is first. Best ways are....

1: Uninstall EVERYTHING that you don't really need and/or don't use.
2: If you really want speed, put Windows back to Classic view with no whistles and bells.
3: Free Download - CCleaner - - excellent tool - check all the boxes - also use the reg cleaner 'Several' times until it comes up with nothing.
4: Free Download - EasyCleaner - - doesn't seem to be supported any more but works very well - Sometimes requires Two installs to stop it freezing but it's still worth it. Check all the boxes in the Unnecessary box. The Reg cleaner is also very good.
5: Free to Try - Registry Repair Wizard - - use 'After' all the other clean-ups - test version cleans 10 at a time, can be repeated to clean all but well worth buying.
6: Run Defrag several times.

7: Let us all know how you get on.

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by luderan1 / July 20, 2007 9:24 PM PDT

Tom D.

What a great question ... I don't have a clue but I anxiously await the answers next week!


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by avaloans / July 20, 2007 9:56 PM PDT

Well my idea is don't get any risk to removing unnecessary files and also extension ,keep these files in your PC and Download latest ccleaner Software from here after that remove these unwanted things by using it

some extensions are very important to run system alike (.sys,.dll,.ini,.inf,)
.tmp extensions can be removed by your self.

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A Word Of Warning
by 1up2down / July 20, 2007 11:57 PM PDT

A word of warning if your using Explorer to delete files, do not delete anything from Program Files or WINDOWS. If it's only your own personal data files, no problem. If it's a program, then don't delete it, remove the program using Add and Remove Programs in Control Panel. But under no circumstances delete anything from WINDOWS.

If it's all those junk files that slow down your computer such Temporary Internet Files, History, cookies, recent documents, event logs and so, then why worry, there are plenty of programs out there that will do the job for you automatically. Some are free but even those that are not are quite cheap to buy. For a free version, I've tried CCleaner and it's pretty good at the job. But personally I'm using R-Wipe and Clean, it's a low priced but very efficient cleaner that can be set to do certain tasks automatically at a time to suit yourself. The only problem I found with it was that when you set it to do tasks on shutdown, you will no longer be able to use restart, it would just go to shut down. So I set my tasks to do their job on startup instead. One thing I can tell you is that you will be amazed at the amount of junk it does find.

Even so, that's not all the junk you'll find. There's also a lot more that many people don't realise is taking up huge amounts of space on their hard drives. If you have Windows for instance, it has System Restore Points, and these build up over a period of time taking up a large amount of space.

As long as your not having any problems with the operating system, I would recommend turning System Restore off every so often to clean off all the old restore points. When you turn it back on, you can make a new restore point and begin again.

To turn off System Restore, right click My Computer, go to Properties, click the System Restore tab and uncheck the box next to Turn off System Restore on all drives. Click Apply and then restart the computer. After the computer reboots, don't forget to go back and recheck the box to turn it back on.

To create a new Restore Point, simply go to Help and Support, click on System Restore, then choose create new restore point and follow the simple instructions. Give it any name you like such My Restore Point.

Personally, I prefer to have my System Restore turned off permanently because I have something much better. I have one of the best backup systems there is, Acronis True Image. If anything goes wrong with my operating system, all I need do is restore the image to put everything back to how it was.

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by strickjh2005 / July 23, 2007 12:35 AM PDT
In reply to: A Word Of Warning

You can delete tons of things under windows. All the bit map images can be deleted. The temp folder can be mostly hacked out. Under windows<web<wallpaper everything can be deleted.

Cursor Icons can be trimmed to the ones that aren't hideous. Prefetch can be emptied, but not deleted. Under media you can remove/add sounds that you want windows to play. If you have a pc you can get rid of low battery and battery critical. If you have already disabled balloon tips like any self respecting person should, you can delete that sound too.

Downloaded installations can be cleaned out.
C:\WINDOWS\SoftwareDistribution\Download can be cleaned out for usually a good 50mb
Go through program files and delete empty folders left behind after uninstallations.

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Welll ...
by drpruner / July 27, 2007 4:14 PM PDT
In reply to: Untrue.

As it happens, my *.bmp search under C\windows showed many that belong to MSWorks, and many that belong to a geometry program I use. The Works is long gone, so the .bmp are, too. (About 3 mb) Thanks for the tip.

Anyway, your post implies careful checking before deleting, but says, "All the bit map images can be deleted". An old hand like me can handle that, but there's lots of tenderfeet out there, Pard. Happy

*.cur search gives less than 100kb of files; hardly worth the effort. And some day one of the lost ones may be useful just because it's different in appearance. Ditto with sounds.

Font files are likely targets. (Do we really need five different stencil fonts?) Also they add up the megabytes and add time to startup. (Although my second-rate system is fast enough ... and I really do like Hip-Hop Stencil.)

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by 1up2down / July 27, 2007 4:19 PM PDT
In reply to: Untrue.

Yes, I quite agree with you, and I too have deleted files from Windows. But when advising someone who obviously has no knowledge of what's safe to delete, the best advice for them is to stay well away from the Windows folder.

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Surely the need for this depends on your hardware?
by gbswales1 / July 27, 2007 6:26 PM PDT
In reply to: Untrue.

Nowadays it is not that unusual for PCs to come with 300 gb or more of disc space - I have a 500gb plus a 300gb I use for back ups - the total cost of adding the 500gb was

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This discussion reminded me of a question,
by drpruner / July 28, 2007 8:24 AM PDT

and you might be the one to answer it.
A couple of years ago I came across a free site that identified just about every "hidden" startup program anyone might encounter on Windows, and (I think) an index to file suffixes (.nnn) etc. Had recommendations for delete/keep. I remember those recommendations were on the conservative side. Do you know what site I have in mind?

Thanks, Doug

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This might be it
by radcad92 / July 28, 2007 8:57 AM PDT
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(NT) That's the one! Thank you very much.
by drpruner / July 28, 2007 9:38 AM PDT
In reply to: This might be it
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P.S. "
by drpruner / July 28, 2007 8:31 AM PDT

Go ahead, Fluellen, rub it in! Happy

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"If you have already disabled balloon tips..."
by winduvscry / July 28, 2007 1:31 AM PDT
In reply to: Untrue.

You can delete balloon tips?!?! HOW?!

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As well
by Steven Haninger / July 28, 2007 3:52 AM PDT
In reply to: Untrue.

If you are sure you are not going to uninstall any MS updates, hotfixes, etc. you can delete the individual unintall folders for these as well as the log files linked to their name. Over time, these begin to eat up a huge amount of space. Drop them in the recycling bin for a time if you're hesitant.

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Haninger!! What are you doing
by drpruner / July 28, 2007 8:28 AM PDT
In reply to: As well

hanging around here?!
There are people's buttons to be pushed over on SE!!


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Man does not live
by Steven Haninger / July 29, 2007 1:01 AM PDT

by (pushing) hotbuttons alone. Haven't you noticed that the help forums are where you can get others to destroy their PCs by taking your advice. Mischief knows no boundaries. Happy

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(NT) LOL!!
by drpruner / July 29, 2007 1:43 AM PDT
In reply to: Man does not live
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Uninstall files
by lablover / August 30, 2007 5:34 AM PDT
In reply to: As well

What files would these be? What is the prefix?
Are you saying just delete them to the recycle bin?

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I got CCleaner for
by drpruner / July 27, 2007 4:24 PM PDT
In reply to: A Word Of Warning

the substantial discount Happy and I like it. I did discover a tip for it that may escape others like it did me.
The default 'what to delete' tab is Windows, and IE is right at the top. I skip cookie deleting, since most browsers have intelligent cookie handling. IOW, if a cookie is there, I'll want it later. But don't forget to go to the Applications tab for any other browsers you have, and uncheck Cookies. It does locate any apps, including browsers, that are likely to have files that need deleting. It even found Foxit Reader, an Adobe substitute, as well as Adobe Reader.

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