PK - I unchecked "Store Files" and accessed Chrome browser virtualized. AD-BLOCK was enabled OK. I accessed U-TUBE and there was no sound again. Same as before, when I clicked another web site Chrome crashed. I shut Chrome down and did a re-boot, but as the computer shut down I got a few dialog boxes, the last of which said dirty shutdown. After it re-booted I virtualized Firefox, and accessed U-Tube with no problems. After I watched a video which had sound, I clicked on a few more web sites with no problems. So I would guess that Avast! virtualization doesn't play well with Google Chrome.(my Chrome at least) I'll switch to Firefox as my default browser until the problem is corrected.