This error typically occurs when your computer has too many applications or processes running and is unable to complete the current request to launch a program or perform a task. Many times two devices are competing for the same I/O port or Direct Memory Access Channel.
When this error occurs you will need to take a few steps to adequately troubleshoot and resolve the issue. The most logical place to start is to look at how many external devices you are running at the time the error occurred. If you have several USB devices running, try removing them one at a time to see if you can get the error to cease. If doing this resolves the error, a good choice would be to buy a USB hub so that you can run several devices on your PC via USB without clashing with another device.
This resolution will not always work as sometimes the root cause is at a deeper system level than can be fixed simply by unplugging devices. To diagnose the problem, go to Device Manager and run the Troubleshooting Wizard. This step should return a report to you about what device is causing the conflict that set off the error message. Take note of the conflicting device and follow the recommendations of the Troubleshooting Wizard. Here are the steps to accomplish this fix:
Older computers that are running Windows 98 or Windows ME are more susceptible to this error. It can happen to a newer Windows 7 PC, but devices are usually assigned resources much more efficiently and these problems occur less frequently.
TipFor more information, please see: How to fix System Resources error #12