If Windows Memory Diagnostic completes the first pass and reports no errors, then your RAM is probably working correctly. It is unlikely that Windows Memory Diagnostic will find any errors with your RAM on subsequent passes using the same settings.
http://oca.microsoft.com/en/windiag.asp#top
I’d say if the first pass was OK, it’s more likely to be a rootkit, or something else.
Have you tried the SdBot removal tools? Try a re-run with the anti-rootkit scanners using the in-depth setting where possible. Are they coming up clean?
