Bloody hell use the holy trinity beaver:

Spybot search and Destroy
Adaware se v1.05
HiJackThis
Any of these prog will only scan the registry of the ACTIVE OS..
you will need to install on each OS and individually scan them..

And be sure to follow nihils advice first
Then empty all browser caches and history, and be sure to empty the Java cache as well
As well empty the c:\windows\temp folder (oh thats c:\winNT\Temp on the Win2k machine)
in winXP clear the contents of the c:\windows\prefetch folder as well, clear the TIF, recycle bin..

OH: BTW: When the malware file is detected WHERE IS IT?

these things WILL set them selves as System Hidden files.. so you need to have an idea where it lives then you can kill it iuseing the command prompt.. you may need to use the attrib command to snot the bugger