It sounds like the infection have corrupted one or more systemfiles.
After You have run the scan tools -
Reboot normally
Post Hijackthis log along with SuperAntiSpyware log, , C: combofix TXT in this topic
Please copy and paste your log. DO NOT add it as an attachment
Kindly do not annotate or format the log with color or font changes.
NB. If you are using any P2P (file sharing) programs, please remove them before we clean your computer.. We do not clean logs that have P2P applications installed as this can cause reinfection during your cleaning.
Do NOT post your problem in someone elses thread.