cmsetac.dll

I seem to have a problem with the file cmsetac.dll because CAV sees it as a trojan but because it is in the system files it can’t be quarantined or deleted. It does not have a Microsoft signature and so is not attached to an official dll. Is there any way of removing it? Probably downloaded with other software(unknown). It is classified as a rootkit podnuha.bqq@17014507.

System specs:
XP pack 3 fully updated
Comodo internet security free version
intel core 2 Duo 2.4

Don’t worry the antispyware programs that were suggested seemed to have taken care of the problem(SUPERAntispyware). Thanks