Please help with virus!

[Maetje]

Hi,
I'm new to this. Can someone please help me analyze my log from HijackThis?
My Pc is starting up very slowly and since two days I haven't been able to save any Microsoft Office files. And a RavMonLog file keeps appearing on my usb stick.

Am I infected. And if yes....what do I do to remove the virus?

Thanks a million!!!