RVHOST.exe causing headaches

Hi there. Can anybody please tell me how the heck I get rid of the RVHOST.exe trojan?

Some information wouldn’t go amiss.

What Operating System are you using ?
What avast! version and VPS file (virus database) number, e.g. 4.7.1074 and 071202-0 (see about avast!) ?

What is the malware name and where was it found e.g. (C:\windows\system32\infected-file-name.xxx) ?
Check the avast! Log Viewer (right click the avast ‘a’ icon), Warning section, this contains information on all avast detections. C:\Program Files\Alwil Software\Avast4\ashLogV.exe

Did avast detect it ?
What action did you choose on detection ?
Why can’t you get rid of it, error messages, etc. it keeps coming back, what ?