When you install a Plug and Play device, Windows automatically configures the device so it will work properly with the other devices that are installed on your computer. As part of that configuration process, Windows assigns a unique set of system resources to the device you are installing. These resources can include one or more of the following:
Each resource that is assigned to your device must be unique or the device will not function properly. For Plug and Play devices, Windows automatically ensures that these resources are configured properly.
Occasionally, two devices require the same resources, resulting in a device conflict If this occurs, you can manually change the resource settings to be sure each setting is unique. However some resources, such as interrupts on PCI devices, can be shared, depending on the drivers and computer.
When you install a non-Plug and Play device, the resource settings for the device are not automatically configured. Depending on the type of device you are installing, you may have to manually configure these settings. Instructions for doing so should be supplied in the manual that came with your device.
Generally, you should not change resource settings manually, because when you do, the settings become fixed, and Windows will then have less flexibility when allocating resources to other devices. If too many resources become fixed, Windows may not be able to install new Plug and Play devices.
You can manually configure devices using Device Manager