Not a lot of tech info at the Symantec site about this one. I did find some success stories.
They involve disabling system restore (turn it off), restarting in safe mode, run the removal tool again, check the registry and remove the following key (if present) HKEY_CURRENT_USER\Software\Microsoft\PIMSRV
Restart in normal mode, run a virus scan, enable system restore again.
I'd try green granite's simpler version first, and if that fails to remove it, try the steps above.
An additional tool that may be effective (it's extremely good) is
MBAM. This is an anti-malware scanner. Install it, update it, then run a scan.
PS, apparently it converts any media files in .mp2 or mp3 format to .wma format, increases their size by 1138 bytes, then causes the media player to link to a malicious link if those files are played. Worst case scenario, you may have to loose some of those files.
It was possibly contracted by allowing/instructing the media player to download "required" codecs. Ring a bell?