Computer shuts down mid-scan! What do i do?

I'm working on try to de-virus my roomate's computer that in her words is 'one step away from the plague'. I've tried to follow the protocol you have posted to do first before everything else, and I've been able to get rid of alot of what was wrong (no more popups at least), but every time I try to run either of the online scans, Spybot, or Stinger, the computer powers off mid-scan, even when I'm in safe mode. It seems that anything capable of detecting the virus or whatever is on the computer automatically triggers a shut-down. Any suggestions on where I can go from here?

 

So here are some specs on the computer in question:

OS: Windows XP Home Edition SP2 version 5.1.2600
RAM: 512 MB SDRAM
CPU: Mobile AMD Athlon XP 1084 MHz (2.5 x 434)
Hard Drives: C: (NTFS) 11460 MB (2639 MB free)
D: (NTFS) 17131 MB (6178 MB free)

Please let me know if there is anything else you need from my end, or if you want me to post my HijackThis log.

 

- Download HijackThis 1.99.1

- Unzip the hijackthis.exe file to a folder you create named C:\Program Files\HJT

- Do NOT run Hijack This from the Desktop, a temp folder, or a sub-folder of C:\Documents and Settings, or choose to run it directly from the downloaded ZIP file.

- Before running HijackThis: You must close each of the following:your web browser, e-mail client, instant messenger, and programs like notepad, wordpad, MS Word etc. And any other unnecessary running programs.

- Run HijackThis and save your log file.

- Post your log as an ATTACHMENT to your next message. (Do NOT copy/paste the log into your post).

 

OK, here is my hijackthis file. Thanks!

 

Download
- Pocket Killbox

First look in Add or Remove Programs in the Control Panel and uninstall the following if found:

Next In HJT Choose Open the Misc Tools Section choose Process Manager, Highlight

Choose Kill Process

Now scan and have HJT Fix the following:

Now run Pocket Killbox:
Choose Tools > Delete Temp Files and click OK.

Run Killbox.exe. Paste the below filenames into KILL BOX one at a time. Check mark the box that says "Delete on Reboot" and checkmark the box "Unregister DLL" (If available) Click the RED X and it will ask you to confirm the file for deletion…say YES and when the next box opens prompting you to reboot now...click NO...and proceed with the next file. Once you get to the last one click YES and it will reboot. Note many of the file list below may not exist but we need to check for them anyway.

If Killbox does not reboot or you get a Pending Operations type error message just reboot your PC yourself.

Now boot into SAFE MODE open Windows Explorer navigate to and DELETE the following:

Reboot post a new HJT log.