BleepingComputer.com: I've tried everything that's been suggested

My PC has been freezing. Before you yell at me this is what I've tried.
•Checked hardware, no yellow ! marks
•Checked memory...all 6 scans 2 passes...nada.
•Checked drivers...diagnostic came up empty handed
•turned off startups...disabled windows services...nothing
•Defraged, disc cleanup, reverted to an earlier state for windows...none helped
•attempted to change Anti Virus Programs since Avira & Mcafee caught nothing...
now I can't install AVG because Mcafee is still present somehow...although
I couldn't uninstall it the traditional way...I googled and found links from threads that led
me to the uninstall tool...which I ran and rebooted...it's no longer in the uninstall options..but
AVG still says it can't Install because of McAfee.

I'm basically posting this now..because I don't see any fixes different than the ones I've already tried.
Can anyone help. I did go through some of the rules and if I broke any of them in this post...I appologize. I'm in safe mode now and my screen size sucks typing this too. Thanks. I'm glad
I was able to get this typed before my PC froze again.
Windows XP, Dell Vostro 410, had it for about 2 years. It's my shop pc...I own a sign shop...this is my
backbone for now. HELP

This post has been edited by Orange Blossom: 08 June 2010 - 09:45 PM
Reason for edit: Move to XP forum from Mini-Guides ~ OB

The below is compliments of Broni:

You may have some hardware problems.

***** Run hard drive diagnostics: http://www.tacktech.com/display.cfm?ttid=287 (or http://www.bleepingcomputer.com/forums/topic28744.html)
Make sure, you select tool, which is appropriate for the brand of your hard drive.
Depending on the program, it'll create bootable floppy, or bootable CD.
If downloaded file is of .iso type, use ImgBurn: http://www.imgburn.com/ to burn .iso file to a CD (select "Write image file to disc" option), and make the CD bootable.

NOTE. If your hard drive is made by Toshiba, unfortunately, you're out of luck, because Toshiba doesn't provide any diagnostic tool.

====================================================================================

A. If you have more than one RAM module installed, try starting computer with one RAM stick at a time.

NOTE Keep in mind, the manual check listed above is always superior to the software check, listed below. DO NOT proceed with memtest, if you can go with option A

B. If you have only one RAM stick installed...
...run memtest...

1. Download - Pre-Compiled Bootable ISO (.zip)
2. Unzip downloaded memtest86+-....iso.zip file.
3. Inside, you'll find memtest86+-....iso file.
4. Download, and install ImgBurn: http://www.imgburn.com/
5. Insert blank CD into your CD drive.
6. Open ImgBurn, and click on Write image file to disc
7. Click on Browse for a file... icon:



8. Locate memtest86+-....iso file, and click Open button.
9. Click on ImgBurn green arrow to start burning bootable memtest86 CD:



10. Once the CD is created, boot from it, and memtest will automatically start to run.

The running program will look something like this depending on the size and number of ram modules installed:




It's recommended to run 5-6 passes. Each pass contains very same 8 tests.

This will show the progress of the test. It can take a while. Be patient, or leave it running overnight.



The following image is the test results area:



The most important item here is the “errors” line. If you see ANY errors, even one, most likely, you have bad RAM.