CNET también está disponible en español.

Ir a español

Don't show this again


Q&A: MacFixIt Answers

MacFixIt Answers is a weekly feature in which we answer questions e-mailed in by our readers. We welcome alternative approaches and views from readers and encourage you to post your own suggestions in the comments.

MacFixIt Answers is a feature in which we answer questions e-mailed in by our readers.

This week people wrote in with questions on preserving an intact preferences file for restoring if the working one becomes corrupt, using an alternative e-mail account with iCloud, an unrecoverable filesystem error showing in Disk Utility, and why not download PKG installer files directly. We continually answer e-mail questions, and though we present answers here, we welcome alternative approaches and views from readers and encourage you to post your suggestions in the comments.

NOTE: The "contact us" box for e-mailing us will hopefully be back soon, but until then please use the contact links at the bottom of each article to send in your questions.

Question: Preserving an intact preferences file to restore corrupt ones
In response to a suggestion of removing the log-in window preferences file to correct a configuration problem, MacFixIt reader Andreas asks:

What do you think about copying the "correct" loginwindow.plist into a secure location, to have one intact .plist in case the normal loginwindow.plist will be corrupted again?

That is definitely one approach you can take in order to be able to quickly restore the preferences file if it gets corrupted in the future. Some people have used Time Machine and other automated options to restore older and working versions of property lists, but a manual backup should do just fine, especially for configuration files that do not change frequently.

Question: Using an alternate e-mail account with iCloud
MacFixIt reader Dan asks:

How can change my e-mail account from "" to [an alternate one] when using iCloud?

The e-mail account associated with Apple's iCloud service is going to be "," but you do not need to use this and can set up any alternative e-mail account in Mail as your main e-mail account. To do this, you can set up your account in the Mail, Contacts & Calendars system preferences, or directly in Mail's Accounts preferences. After you do this, go to the iCloud system preferences and uncheck the Mail & Notes option to disable the iCloud e-mail account if you wish.

Question: Unrecoverable filesystem error showing in Disk Utility
MacFixIt reader Eddie asks:

I have a Western Digital 1 TB drive hooked up via FireWire to my Mac (see details in previous email). It has stopped showing up on my desktop. When I run Disk Utility, it reports the following:

Verify and Repair disk "My Book"
Invalid Volume Header
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Invalid node structure
Volume check failed.

Error: The underlying task reported failure on exit

1 HFS volume checked
1 volume could not be repaired because of an error

Can you suggest anything that can repair this without having to back up, erase, and re-load (like DiskWarrior)? A free solution is preferable, but I'll consider any suggestions.

Unfortunately fixing this type of problem depends on the nature of it and whether or not a third-party program can detect and correct it. Disk Utility should be able to do this, but it is not the best at correcting these issues. There are some free tools for correcting disk issues; however, they are terminal-based and are not easy to use. My recommendation would be to use DiskWarrior or a similar tool like Drive Genius, TechTool Pro, or Disk Tools X to try correcting the problem, but these will cost a bit and not be guaranteed to recover the drive.

There are a number of "free" tools that will check drives, but most of the free ones just interface with Apple's built-in disk utility commands and do not offer any new "fixing" technologies.

Optionally you can try using a file recovery tool that can scan the drive and try to extract file patterns off of it, but this is usually a last-resort option for recovering data and can be a very hit-or-miss operation.

Question: Downloading PKG installer files directly
MacFixIt reader Ian asks:

Just read your article on DMG files and occasionally someone will put a .pkg file within a DMG file. Why can't they or us download it as a .pkg file rather than a DMG file. You also have people putting a DMG file within a .zip file which I found doesn't reduce the size that much and should have left it as a DMG.

The DMG file helps protect the active files (in this case the PKG) from being tampered with. The DMG file contains a checksum for its contents that help determine if they have been corrupted. If a PKG file is corrupted then it may cause system problems if you install it; however, if the DMG file "wrapper" is corrupted then it will just not open.

Lastly, PKG files and applications are not individual files, but instead are "packages" that are essentially special folders with a number of files within them. This structure prevents some Web services from managing packages as files, and can cause corruption in them if downloaded directly.

There is no benefit to putting a DMG file in a ZIP file, but ZIP files and other archiving file types have historically been used for electronic downloads so some distributors may just be sticking to convention.

Questions? Comments? Have a fix? Post them below or e-mail us!
Be sure to check us out on Twitter and the CNET Mac forums.