
Hi Chao, Memtest needs to be booted from off of a floppy or CD. If you don't have a floppy drive, you will need to download the bootable CD version and use a utility like Nero to burn it into a bootable CD. Here is their main page, it should have all of the information that you need, and any other downloads if you need a different version,
Memtest86 Mainpage
Everything I have ever read about Memtest as well as all the times I've had success with using it to troubleshoot, recommend allowing the test to run overnight to thoroughly check your
RAM.
If the test runs all night and shows no
RAM problems, the next troubleshooting step is to return the card, and get a new one. If you are still having the same problem, we will have eliminated most of the possible issues, and it may be worth checking out malware as a culprit, although, as I said previously, this just doesn't sound like a malware issue.
Looking forward to your reply,
TTFN
LGW