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I recently ran Disk Cleanup (with the "compress old files" option) and Disk Defragmenter on a PC with Windows XP. This computer was purchased in 2004, and was a "middle of the road" computer at the time. After using it, I tried to open a relatively new invoice file with "Simply Accounting" and it hung. I decided to restart the PC, and it then worked fine. I also installed and activated the Free AVG antivirus 9.0, and ran a virus scan (no viruses found).

My questions:

  1. Did running Disk Cleanup, Disk Defragmenter, or Free AVG cause something to slow down file access for Simply Accounting? If so, will this be a permanent problem? If so, is there any way I can reverse it?
  2. Does Free AVG 9.0 being active cause reduced performance? If so, are there better free antivirus programs?

I appreciate any help you can offer.

Thanks, Jay

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Have a look at Microsoft Security Essentials instead of AVG, but primarily I'd look at increasing your RAM. Adding another 1GB is usually a life changer on holder hardware. – user3463 Aug 6 '10 at 15:28

File compression can cause problems like this. I experienced this a lot at my job when customers would use compression and it would compress database files for SQL Server. Some programs just won't work at ALL with files they need to access compressed.

Uncompress at least all the files for that program, and see if it fixes it. I would recommend uncompressing ALL your files, since it could be a shared .dll in the Windows folder that is causing the issue, or otherwise a file not in the directory tree structure for that program.

For #2, all AV programs that run real-time protection will reduce performance slightly (normally it's not noticeable). This is the price you pay for having every file being access scanned before it can hurt you. I use Avast and it works fine, and is also free, if you want to give it a shot. AVG should be fine, though, unless they have really changed something in the most recent version.

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How would I uncompress those compressed files? And how would I know if a particular file was compressed? – Jay Godse Aug 6 '10 at 17:16
@Jay - in XP the compressed files show with a blue font in windows explorer. To decompress files, select them, then right click, Properties -> Advanced -> Uncheck "Compress contents..." You can do this for a whole folder as well, but it may be a slow process. – JNK Aug 6 '10 at 17:29

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