Whenever I insert a flash drive disk (or anything for that matter) in any of my computers' usb slots, my compter immediately locks up. I have to restart the computer to get it working again. Any ideas what is causing this problem ?

Is this a new problem? Any new hardware or software?

If the problem is new try a System Restore to a point prior to the problem.

start > All Programs > Accessories > System Tools > System Restore

Do you mean any usb device (not just the flash card) plugged in causes the problem?

Do you mean it does not matter which usb port you plug in, it just does the same thing?

Are all those usb ports adjacent to each other? do you have any other ports not close to those that are causing the problem (such as in the back of the computer).

If any usb device plugged into any port causes that, there is a chance that it is power related.