|And again... did you disable system restore before scanning? If you don't.. it's quite likely the pests will be "restored" afresh..; which is why one disable XP system resotre (so as to prevent this....).|
Also often better to scan in safe-mode (with networking) and with system restore disabled as above...; that scan being the locally installed scanner, and/or via an on-line freebie... (I'd do both.)
When scanning with local util - disconnect from www.
And also as above... did you do a Knoppix/Ubuntu boot to run an on-line freebie scan (avg, or Housecall etc...)?
Before you set about disconcecting drives etc. (and reformatting)... go thru the above. If problems persist (and they may/may not...) then consider the reformat approach.
It depends on what drives you have, and how they're connected - Master/Slave relationships, or cable-se;ect? In the former arrangment there will be jumper to change on the Master drive; if the latter no jumper(s) to worry at this time/in that case...