Conflict troubleshooting

The PC provides only a limited number of interrupts (IRQs), DMA channels, and I/O addresses for devices to use. No two devices can use the same resources-if the same resource is assigned to two devices, they will compete for control. Conflicts can result in problems ranging for erratic device behaviour to system lockups and crashes. The procedure below offers a reliable method for locating and eliminating device conflict:

• Power the computer down and remove the new expansion device.
• Start the machine to the DOS mode and run the MSD.EXE program that is in your \WINDOWS directory (you can also try any number of shareware or commercial diagnostics that detect resource assignments).
• The program will let you look at which interrupts, DMA channels, and I/O addresses are currently in use on your system. Record those on a sheet of paper (or print the report to a printer) and exit the program.
• Examine the new device and check its resource assignments against the resource already in use. Chances are that the new device will be using an IRQ, DMA, or I/O assignment already shown in your MSD report.
• Change the conflicting resource. For example, if you find and IRQ conflict, change the IRQ on your new device to an IRQ that is not in use. If the device's resources are set through software, simply proceed to the next step.
• Turn the system off again and place the device back in your computer.
• Run any setup software for the new device. It should be recognized properly.
• If you cannot find any available resources, you will have to disable at least one other device in order to free up the resources for your new device.
• If the new device works under Windows, be sure to run any Windows installation software. If the device is running under Windows 95, run the Add New Hardware wizard.