Under windows 8, if I tell NIS to turn off virus detection for 15 minutes (say), in order to install some new software without a virus scan, Norton will not re-enable the virus detection. It won't turn it back on automatically at 15 minutes, and it won't allow me to manually turn it back on. The only solution I've found so far is to uninstall Norton, and then reinstall it. Upon reinstallion all is well, but this is a really irritating bug.