Suspect Memory

While many people I know have always suspected my lack of ability to remember peoples' faces, but remember numbers and useless trivial knowledge, I'm talking about RAM.  My laptop has been performing strangely ever since I upgraded to a gig of ram from the onboard 512mb.  It'll do things like blue-screen XP after an hour of idling (forget about actually doing work).  So to that end, I'm doing some serious testing of the RAM to make sure I didn't get any bad chips (I'm almost positive I did).

Enter Chris Brady's Memtest86, a free program loading from a bootable disk, that simulates normal RAM operations on a systematic scale, writing to and reading from each location in ram, and then checking for errors. This program is easy to use and free, under the GPL. There's also ISOs available if the machine in question does not have a floppy drive.