A worn keyboard or signs of a key logger. Be sure you scan with Grif's list at
http://forums.cnet.com/7726-6122_102-5509131.html?tag=posts;msg5509131
Be sure you didn't accept drivers from Microsoft's Windows Update.
Bob
The hot keys (very top row) work only intermittently for some unknown reason. To change volume, all I had to do was hit the single key for up, down, mute. Also the F2 and F3 keys changed brightness by hitting the single key. Now they are not working at all. I've had laptop for over two years and up until now all was OK. And please don't tell me I have to simultaneously be pressing on the Fn key to make them work. I get that a lot.
I must be doing some inadvertent action that is acting like a "switch" that is turning the feature on and off.
Any help would be appreciated.

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