HELP ME - blue screen installing MS Malicious Software Removal Tool

[Sanchez]

I have winxp SP2

If i try to upgrade winxp and install MS "Malicious Software Removal
Tool" my system crashes
and i receive this blue screen
http://img100.imageshack.us/my.php?image=scbluoa9.jpg

someone told me try to install KB900485, but also installing that
upgrade my system crashes and receive this blue screen
http://img100.imageshack.us/my.php?image=scbluoa9.jpg

what can i do?

my AV karpersky and adaware don't find malicious sw...

HELP ME, pleeeeeeeeeeeeeeeeeease.

 

[NewScience]

Have you tried turning off all your AV programs prior to install?

Have you CHKDSK /r you hard drive lately?

 

[Sanchez]

NewScience ha scritto:

Have you tried turning off all your AV programs prior to install?
yes

Have you CHKDSK /r you hard drive lately?

no... what i have to do exactly?