to get rid of this entry:
O23 - Service: MSIn Task Manager (MSItsk) - Unknown owner - C:\WINDOWS\system32\MSIntskmngr.exe
You can go START > RUN > type in;
services.msc
In the next window, look on the right hand side for this service name:
MSIn Task Manager
Double click on it and STOP the service
In the drop down menu, change the startup type to "Disabled"
Open Hijackthis > Open Misc Tools Section > Open" Delete an NT Service"
In the new window, type this --> MSItsk
into the Open field and hit OK
Maybe scan with Rootkit Revealer or Blacklight as already suggested.
You can also scan your system with Kaspersky's online scanner just to get all the infected files, Kaspersky won't delete them but at least you get to know where they are located.