Microsoft has another virus scanner you may consider that may be better than it’s other tools – Microsoft Safety Scanner.
I would try the System Sweeper first and then try this program. \
System Sweeper creates a CD which you can boot from and then run the scanner to look for viruses.
Of course you need to download and install this from a non-infected computer.
You also need IMAPI v2.0 installed on the computer in which you burn the disk.