With this new partition, maybe you can:
- Disable System Restore (in all partitions) and reenable it after step 3.
- Clean your temporary files.
- Schedule a boot time scanning with avast with archive scanning turned on.
- Use AVG Antispyware; SUPERantispyware and/or Spyware Terminator to scan for spywares and trojans. If any infection is detected, better and safer is send the file to Quarantine than to simple delete than.
- Test your machine with anti-rootkit applications. I suggest AVG or Trend Micro RootkitBuster.
- Run a full computer on-line scanning:
Kaspersky (very good detection rates)
ESET NOD32
Trendmicro housecall
AVGas (does not necessary if you have AVG antispyware installed)
F-Secure
BitDefender (free removal of the malware)
HitmanPro (multiply scanners)