USB seems to lose contact with keyboard and mouse

[Wandering Inquizitor]

I have a problem with my USB ports I have not been able to remedy.

USB's will occasionally lose the mouse and then reconnect.
USB's will power and recognize keyboards but after a while they seem to stop taking in input.
All USB ports seem effected (including the USB 3s).
Once a port stops taking keyboard input, it only does so again after I disable the port in the device manager and restart.
USB's always lose connection and then reconnect with the mouse when a person physically passes by the PC tower (no kidding, I have no idea...).
USB port connected printer suffers no problems on any port.

I've tried several different mouse and keyboard units, all have the same problems.
I've tried uninstalling the USB ports but no luck there.

I am entirely at a loss what to do next. Any ideas on what this problem could be or possible solutions or tools to narrow down what could be wrong? I am running Windows 7 64 bit and I keep my drivers up to date.

Thanks

 

[hang-the-9]

Check for a BIOS update for the motherboard, reseat the power connectors. Does this happen to both onboard and case ports? Have you tried with different keyboard/mouse to make sure one of them is not causing a power surge issue? Did you try using different combination of ports? So if you use 1,2,3, try using 2,3,4 then 3,4,5 etc... to see if one of them is bad.