Hi, I have Windows XP on a Thinkpad with 512 MB RAM preinstalled and one additional 1024 MB RAM chip. The system worked perfectly for over a year. Unfortunately, I suddenly started getting BSODs even though I installed no new hardware or software. I removed the 1024 MB chip and the errors stopped. I then ordered a new chip, but I quickly got the same "memory_corruption" BSODs, so I removed the new faulty 1024 MB chip. Unfortunately, now I get new BSODs about once a day, even with just the one MB chip. I followed all the steps you listed to no avail. I am attaching some Bugcheck analyses. Mini111306-01 is a BSOD with both sticks of memory. The remaining errors are with just the 512 MB system RAM. The errors with both RAM chips are usually IRQL_NOT_LESS_OR_EQUAL, and the errors with only the 512 MB chip are usually BAD_POOL_CALLER or KERNEL_MODE_EXCEPTION_NOT_HANDLED_M. Thanks so much for all the help! Next time, I'll get a Mac and save me (and you) the trouble.