I never used 'Constant Guard', it was just installed as an update to the Norton 360 install from Comcast. It has a suite of personal security tools including an anti-keylogging feature which apparently went berserk. We have a desktop reserved for the kids to web browse and to do their homework research on during the school year. Wife emails me at work telling me the keyboard won't input anything but the numbers 0123456789. Also tells me multiple restarts failed to clear the issue. OS is XP Home edition. I get home and sure enough, if you open a browser, any browser field inputs from the alpha keys appears as numbers. Check event logs and see the Constant Guard service had errored and failed to start. Checked services and sure enough, it's not started. Deleted Constant Guard and the problem cleared.