System retore messed up my Avast5 Antivirus, too.....twice in the same week. The restores worked OK, but Avast crashes everytime I do one. I jsut can't live without System Restore, so I've had to regretfully uninstall Avast5 until this bug is fixed. Reverting to MSE and will keep checking back to see if this if fixed, Tech. I want my Avast back, but can't accept having to jump through 50 hoops every time I do a restore.