I'm running Windows 7, the keyboard works fine as long as I'm using it but when I leave the PC for hours and try to work after that, the keboard doesn't work and I have to use the on-screen keyboard to login and continue working on the on-screen keyboard only. The only way for the keyboard to work again is if I restart the PC. Is there an option that I have to check or something? Anyone knows how to resolve this problem .. Thanks
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that's probably to do with your keyboard itself, I recommend that you get a new one.
when I leave the PC for hours
When you do that doesn't your pc go to sleep mode? After resuming it happens?