Originally Posted by slosvt
My HTPC contains a 2tb HDD, so the file is local.
Okay, I understand now... I thought in your other post you meant server
stutter, but I now know you were actually saying severe
Since the issue is local, and it just started happening recently, the next question would be... do you do backups of your system with a backup utility -- like Norton Ghost or Acronis, or something similar? If so, try restoring your system to your last saved backup image/snapshot and see if the issue is resolved.
If you do not run a backup utility, you should probably start doing so, because they are invaluable tools for recovering from virtually every software-related issue, from minor headaches like your madVR problem, to major catastrophies like a virus infection.
Even without a backup utility to fall back on, however, you still have another alternative to try and restore your system. Try rolling back your system to an earlier working configuration with Windows Restore Points, which is available natively in Windows 7.
Please keep us posted, and good luck.