If all of the trouble happened after ffdshow, then try using System Restore to go back to a date before you installed that. Note: I said system restore and not system recovery. System restore just fixes Windows and won't mess with your files or anything.
If that doesn't work, you may need to uninstall your Adobe software, run the Adobe Cleaner, and reinstall your Creative Suite.
If that doesn't work, you may need to format your computer and start over. (Backup your files first, obviously.)
You should never ever use system restore to uninstall programs. Frequent use of system restore will totally mess up your computer. It is for example known to break programs and their uninstallers, thus creating new problems instead of solving things. System restore should only be used as a last resort when all else has failed.
You remove software by uninstalling it through: Windows Control Panel > Software.
Sorry, I should have specified that you should uninstall and then run system restore.