After Windows boots and works for several hours, the Setup > Antivirus protection in advanced mode stops working properly. I can't disable the antivirus protection at all by clicking on the "disable" link, and if I click on Configure and try to disable the real time protection there, the configuration window refuses to close if I click OK. The only way to close it is to click Cancel, but then it won't pop up at all if I try to open the configuration window again. The disable email and web protection links actually do work, but the interface fails to update, meaning that the Protection Status indication turns yellow, while it still says that the protection is enabled. After switching to another sub-menu on the left and then back to the antivirus protection menu, then the interface is updated. Same thing happens when enabling back the two modules. After Windows is rebooted, everything goes back to normal, but in a few hours of ordinary use (i.e. browsing, chatting, playing video), the issue appears again. http://img172.imageshack.us/img172/526/2copysm3.th.jpg http://img357.imageshack.us/img357/8875/1copydp5.th.jpg edit: I did some more testing and discovered that when the described issue occurs, the real time and web protection are completely disabled, even though the Protection Status says that system is secure. I downloaded the eicar.com test file and it wasn't detected while downloading or when being written to disk. I suppose the email protection isn't working either but haven't tested it.