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General discussion

Outlook.pst

Dec 7, 2005 2:20AM PST

i have office 2003 installed on my XP SP2 machine, i dont ever use outlook, yet my outlook.pst file is about 1.34gb, the file is located in
C:\Documents and...\...\Local S...\Application Data\Microsoft\Outlook

would it be ok if i delete this file? or does it serve some purpose to anything other than outlook?

Discussion is locked

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Re: outlook.pst
Dec 7, 2005 11:49PM PST

Try to compress it. What size does it become?

Kees

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Re:
Dec 8, 2005 8:09AM PST

it might take a while to compress 1.34gb, does the file do anything?..cant i just delete it?

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Strange
Dec 9, 2005 3:03PM PST

I am a real pack rat when it comes to e-mail, and my outlook.pst file isn't one tenth the size of yours. Either you have some giants in there or a ton of normal-size entries. Have you opened Outlook and looked in its various folders to see what is there?

What are you using as your email client? Normally, when you include Outlook as a component of Office it is set up as your default email client. If you define some other email client as your default, Outlook Express for example, email should no longer be routed to Outlook and then to the .pst file. But since that file is normally mostly email, where then did its size come from?

If you never use Outlook, then you probably should remove it. This can be done by using the install wizard on the Office CD, choosing Add or Remove Features, and unchecking Outlook.

Hope this helps

Frank

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Re:
Dec 10, 2005 1:11AM PST

hmm, so i uninstalled outlook and the .pst file is still there, i want to delete it, but i`m not sure if it serves some purpose, considering its size and the fact that i NEVER used outlook for anything..anyone have any idea if it serves some other purpose for office or somethin?

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Yes, there are some other programs
Dec 10, 2005 3:29PM PST

that use the .PST extension for their files. A search provided the following users: BMail, a bulk mailing program is one -- but I hope you are not a spammer. PST is used for the Lahey Fortran paste buffer -- but this is rare as Fortran is seldom used for programming PCs. The Microsoft Exchange Address Book uses this extension, but the size makes this unlikely. The Ulead Pattern image format also uses .PST; however, their data would be stored as many individual small .PST files rather than one giant one named outlook.pst, as in the case of Outlook.

In Outlook all the personal folders and their individual files, which generally is mostly email, are embedded into a single large file named outlook.pst. There may be dozens of folders and hundreds of files embedded in this single file. That is why it can be very large, but rarely in the GigaByte range. There is one such file for each user of the PC.

You say that you have never used Outlook, so how did its data file get so much stuff in it? Perhaps it was being used without you being aware. I have heard that some other email clients actually use Outlook for their purpose. (BTW, you never answered my question about what client you are using for email.) I suppose it is possible that your machine was hijacked and the hacker was using your Outlook for nefarious purposes. It is too bad you did not look and see what was in these embedded folders before removing Outlook. That might have provided an important clue as to the source of these files.

So, not knowing the source and contents of this file, and with Outlook now gone, it appears to be of no use. However, I would still follow the common procedure for such unknowns -- first rename it (something like outlook.xst or inlook.pst), then if your operations do not need it for a month or so of regular use, delete it. And I would follow Kees' suggestion to compress it to regain some of the drive space immediately. An alternative would be to move it to a DVD, from which it could be recovered if later needed.(I doubt that it could be compressed enough to fit a CD.)

Because of the possibility that this file came from an intrusion, I would run a complete suite of anti-malware -- checking for and removing viruses, Trojans, spyware, and any other baddies that can be found. This forum posting lists some excellent ones you can choose from if you do not already have your own favorites.

Hope this helps

Frank

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Re : Thanks
Dec 10, 2005 11:01PM PST

Thanks for the suggestio Frank, about the email client, i never used any, i normally just use 2 online services Gmail and Hotmail.I think i`ll re-install outlook and see what the file has in it, otherwise i`ll try renaming it, after that i`ll just delete it if its not missed. About the possibility of a hijack attempt, i`m not sure, but i have MS Antispyware and Lavasoft Adaware and i perform regular scans, the most that normally is detected is cookies.I`m also running Norton Systemworks 2005. I`ll try your suggestion, thanks again.

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think i figured it out
Dec 11, 2005 6:12AM PST

ok, so now i feel kinda stupid for not just loading outlook and checking what was in the .pst file, anyways, i reinstalled outlook and did just that, it appears someone had tried to send an email with 2 iso files attached, which made up about 1.3gb together, i guess that could account for the .pst file being 1.4gb, but the thing is, i deleted the unsent email with the attachments, deleted it from the deleted items etc., yet it had no effect on the size of the file, it still stays at 1.4gb. Eventually i just renamed it to a .txt, if my system doesnt miss it within a week or 2 i`ll just delete it. Thanks for help guys.