Keyboard mapping gone haywire ?????

Can anyone help ????Suddenly my keyboard has started playing up. I initially found that on my Microsoft IntelliType keyboard that when I hit the <.> it would produce a . (stop char) followed by a CRLF (Enter key). Also, hitting would produce XX and would produce p. (letter p and a stop).I tried redownloading the keyboard drivers from Microsoft, but no joy. I then tried swapping with an older standard 102 key keyboard. This resolved the odd key responses, but now I find that none of my key combinations are recognised. Obviously this causes a nightmare in Flightsim.This is a cry for help - can anybody offer advice as to where the problem may lie ????HELP?Regards,Stuart Hyett