USB Keyboard or Mouse May Not Work After You Restart Your Computer in MS-DOS Mode

Your Universal Serial Bus (USB) keyboard or mouse may not work after you restart your computer in MS-DOS mode.

This problem can occur under either of the following conditions:

• If USB legacy support is disabled in the basic input/output system (BIOS), or the BIOS does not provide USB legacy support.
  
  -or-
• If BIOS USB legacy support is enabled and the USB Host Controller resource settings were modified by a Plug and Play resource rebalance. This can occur when you hot dock a device, such as a Personal Computer Memory Card International Association (PCMCIA) card.

This behavior occurs because you cannot use a USB keyboard or mouse in MS-DOS mode without BIOS USB legacy support because the operating system uses the BIOS for device input; without USB legacy support, USB input devices do not work.

The operating system disables USB legacy support for 32-bit USB drivers to work. Windows typically re-enables USB legacy support when you restart your computer in MS-DOS mode unless the USB Host Controller resources have changed from the values that were assigned during Startup.

The operating system cannot restore BIOS-designated resource settings. If the current input/output (I/O) port settings are different from the BIOS settings, the device may be inaccessible and your computer may stop responding (hang).

There are several methods that you can use to work around this behavior:

• Use a PS/2-style keyboard or mouse.
• Enable BIOS USB legacy support. For information about how to do this, view the REFERENCES section in this article.
• If BIOS USB legacy support is enabled and you hot dock devices, you can configure the USB Host Controller Resource settings to match the settings that are assigned by the BIOS.

How to Set the USB Host Controller to Use BIOS Settings

To set the USB host controller to use BIOS settings:

1. Refer to your computer documentation for information about how to obtain the device settings from your computer BIOS.
2. Click Start, click Control Panel, and then double-click System.
3. Click the Device Manager tab.
4. Click to expand Universal serial bus controller.
5. Click manufacturer_name PCI to USB Host Controller (where manufacturer_name is the name of the manufacturer), and then click Properties.
6. Click the Resources tab, and then click to clear the Use automatic settings check box (if the check box is selected) to disable automatic settings.
7. Click Input/Output Range, and then click Change Setting.
8. Click the BIOS value for the device. If the conflict information indicates that there is a problem with the device, you may need to modify the settings for that device.For additional information about device conflicts, click the article number below to view the article in the Microsoft Knowledge Base:
   133240  (http://support.microsoft.com/kb/133240/EN-US/ ) Troubleshooting Device Conflicts with Device Manager
9. Restart your computer.
10. If the Use automatic settings check box is selected, follow these steps again and start with step 2.

This behavior is by design.

For additional information about how to use Device Manager, click the article number below to view the article in the Microsoft Knowledge Base: For additional information about problems that you may have with BIOS USB legacy support, click the article number below to view the article in the Microsoft Knowledge Base: You can typically enable or disable USB Legacy support in your computer BIOS settings if your computer BIOS supports this feature. For information about whether your hardware supports USB legacy emulation, view the documentation that is included with your computer or contact your hardware manufacturer.For information about how to contact your hardware manufacturer, visit the following Microsoft Web site: