Sorry if this thread is a tad old, but I see a lot of people (mostly with new computers) having problems with their computer BSODing on new systems running Windows 7.
I found an instant fix (for me at least) and thought I'd post on this thread because it was the most recent and relevant I could find on the forum.
If you hit start then type in 'services.msc' hit enter, then click on the service tab, scroll down and find 'windows search' right click > properties. Then disable.
My theory is that when people install windows on a computer with pre-existing hard-drives it's putting a lot of system resources into indexing these directories which causes the system to hang, or even worse, BSOD.
This fixed my problem of windows crashing when trying to do anything other than one task at a time.
Of course I also installed the correct drivers for my PC before trying any of this, and you should too.
EDIT: You might want to personally re-able the search function before you leave your computer for the night so it can catch up and do all the work while you are alseep of indexing your files for you. I also want to mention I have 3 hard drives with a minimum of two partitions loaded with thousands of files (mostly due to games like FFXI, WoW, and others that have dozens of small files per folder) which could potentially make these problem worse for me than others.