I saved a .wav file from Adobe Audition -with markers- and tried to open it with soundforge hoping I could use the markers. The CPU went crazy! I had to force close both programs and explorer.exe.
On restart the .wav file was untouchable -I was unable to delete or move the file or even check properties -the CPU (all four) goes to 100% in each attempt. This is also true in Safe Mode!
Anyway, I did copy the whole folder containing the file onto my USB stick and open the file in Soundforge on my XP laptop (no markers), so I saved it as a new file (without metadata) and deleted the old one.
Strangely, when I checked the properties of the folder (on laptop), it had the 'Read Only' box checked, so I unchecked it, clicked 'Apply', and closed the Properties window. When I rechecked the properties, the 'Read Only' box was ticked again!
At least I was able to delete the whole folder containing the file on my Win7 desktop and replace it with the new folder.
I know it has something to do with Adobe and file associations because a similar thing happened years ago on my XP laptop. In that case it was image files associated with adobe photoshop. (I had to unassociate photoshop with all image files.) It's really unlikely to be virus related (I'm not connected to the web, I've not installed anything for years, or copied files from other computers until lastnight.
Anyway, I unfortunately copied the .wav file to my desktop where it remains. There's nothing I can do with it now. Had it been copied to a folder on my desktop, I'm sure I would have been able to delete that folder. Weird.