Have you installed any new hardware recently? If not how long has the error / stop been occurring?

If no new hardware have been installed try booting in safemode and try a system restore to a date before the errors began.

the newest hardware installed was a 1gb RAM, which was installed about 1/2 year ago. the problems have been off an on for a couple of months

If you drag the dump file into notepad, or open the xml file and slide yur eyeballs over them you may see a clue as to what is going on, ...or off, actually. A process name will be reported somewhere in there as failing, or a service, driver.. I dunno.

I don't quite get what you mean gerbil. Also though when I'm not running any programs and the computer has been idle for a few seconds the CPU usage is kinda high, like 30-60%. Could the restarts be due to CPU usage problems?

Sorry, but I am in no way an expert on interpreting minidumps. I was just hoping that if you dragged this file, Mini101008-02.dmp into a fresh notepad you might get a clue as to your problem. This one, sysdata.xml, will open in Internet Explorer. But the problem could derive from a hardware issue as vhex suggested. An easy check to make is to turn off the puter, unplug the power, open the sides and unplug/replug everything in sight, including the RAM sticks but excepting the heatsink and processor. If you have multiple RAM modules try with just one.
High CPU usage should not cause the sys to restart, just delay the processing of non-urgent interrupts. Could easily be a malware issue. Try this as a shot in the dark:
==Please download Malwarebytes' Anti-Malware
from: http://www.majorgeeks.com/Malwarebyt...are_d5756.html
or: http://www.besttechie.net/tools/mbam-setup.exe
=Dclick that file, mbam-setup.exe, to install the application, then ensure that it is set to update and start, else start it via the icon.
Select "Perform Full Scan", then click Scan; the application will guide you through the remaining steps.
Make sure that everything found is checked, and click Remove Selected. Examine the log: if some files are listed as Delete on Reboot then restart your machine before continuing.
Post the Notepad log [it is also saved under Logs tab in MBAM].
And then follow up with this scan:
==download hijackthis: http://www.majorgeeks.com/download5554.html
-copy it to a new FOLDER placed either alongside your program files or on your desktop and then... rename hijackthis.exe to imabunny.exe
-in that folder start HijackThis by dclicking the .exe; now close ALL other applications and any open windows including the explorer window containing HijackThis.
-click the Scan and Save a Logfile button. Post the log here.

Here are a couple of sites that offer memtest software [free]
http://www.memtest.org/
http://www.memtest86.com/
http://hcidesign.com/memtest/
The most thorough RAM tests are those done from bootable media... eg cds, cos Windows won't allow access to the part of RAM that it happens to be using.