Win 7 usb keyboard double strikes? Why?

[Smokey7]

For years, no problem. But, over the last 6 months or so the keyboard prints 2 characters for each keyboard letter pressed - but only after the pc has been on for a short while. Always starts out fine. Then, press 'a' get 'aa' etc. Unplug the keyboard and plug it back in and all ok then for the rest of the session. Driver reports it's the latest and is the one that's been in use before the problem showed up. Tried deleting it and letting the pc find one - same problem. Keyboard is a Microsoft one - replaced it with a Novatech usb keyboard. Nothing changes so it's not the keyboard.
Please does anybody have a solution to this?

 

[JeffMD]

You are assuming it is not a hardware issue

 

[pcgeek11]

Change USB Ports....

 

[corkyg]

Since changing KBs does not change the problem, it could be a windows setting that applies to any connected KB. To check that, go to Ctrl Pnl, and Devices/printers. Right click on the KB to check properties. That is where repeat rate etc. are set.

 

[Smokey7]

Thanks for your replies.
Changing usb port doesn't solve the problem and the fact that it's always ok for the first 30 - 60 minutes or so after powering up eliminates Windows settings doesn't it?
Anybody else got any ideas? The PC works just fine apart from this.
I unplug the keyboard and plug it back in again and it works ok for the rest of the day.

 

[bononos]

Could it be some application screwing things up. Or maybe its the motherboard when things are warmed up.