Problem still happening on my Dell 8200 with Windows XP PRO SP3 .. when I first boot up, all are enabled and about 5 minutes later, I find the Behavior Shield has disabled itself. It can be reenabled and seems to stay (can't say for how long as I typically will use this computer for about 2 hours) .. This has not happened on the Toshiba Laptop with Windows 10 Home 64 Bit OS .. This is Avast Free 17.4.2294 (build 17.4.3482.0) ... and yes, I tried a Repair of Avast yesterday. Needless to say, this is annoying.