Mouse and keyboard issues with correction check list:

1) Try Different USB ports.
2) Try Different PS/2 ports (the circle ones purple and green)
3) Try using 1 device as USB and another as the PS/2
4) If wireless, make sure the receiver is on.
5) Make sure there is a clear path of visibility.
6) Is there accumulated dust on your system components (Power Supply Fan, CPU heatsink, Video Card, Motherboard, etc..)?
7) Is your keyboard properly installed using the software CD's from the manufacturer?
8) Are all of your drivers updated?
9) Are your USB port drivers updated as USB 2.0?
10) Delete your mouse and keyboard and reinstall them letting windows selecting the drivers. (Sometimes using the built-in drivers negates compatibility issues)
11) Is there any Interrupt Request (IRQ) conflicts? (sometimes USB can take over position of another device and sometimes another device can take over position of USB which makes a malfunction)

Here is a list of default IRQ's

IRQ 0 System Timer
IRQ 1 Keyboard
IRQ 2 Cascaded with IRQ 9
IRQ 3 Default COM2 and COM4
IRQ 4 Default COM1 and COM3
IRQ 5 LPT2
IRQ 6 Floppy Drive Controller
IRQ 7 LPT1
IRQ 8 Real Time Clock
IRQ 9 SEE 2
IRQ 10 Open
IRQ 11 Open
IRQ 12 PS/2 mouse or Open
IRQ 13 Math Coprocessor
IRQ 14 Primary Hard Drive controller
IRQ 15 Secondary Hard Drive controller


To view your current IRQ assignments open Device Manager.

1. Click on START, click on CONTROL PANEL.
2. Click on Performance and Maintenance.
3. Click on System.
4. Click on the Hardware tab.
5. Click the DEVICE MANAGER button.

Once you have Device Manager open, select VIEW from the toolbar menu and then click Resources by Type.

If you do have a conflict and need to change an IRQ setting:

1. Right click on the device in the list (see above) and then select properties.
2. Click the Resources tab.
3. Remove the tick from the Use automatic settings option.
4. Select a non-conflicting configuration from the pull down box.
5. Click OK



This is all of my theories. Chances are in my opinion if the drivers are fine, if the devices are fine and the settings are fine it is a PHYSICAL problem. Most likely due to over heating or taxing the processor. In most cases if you're playing games you can consume too many or maximum resources and it can cause crazy behavior from your computer.
The last thing I would suspect is the motherboard itself. Generally they don't malfunction unless it is degradation from heat or misuse.