Learn about the technologies behind the Internet with The TCP/IP Guide!
NOTE: Using robot software to mass-download the site degrades the server and is prohibited. See here for more.
Find The PC Guide helpful? Please consider a donation to The PC Guide Tip Jar. Visa/MC/Paypal accepted.
View over 750 of my fine art photos any time for free at DesktopScenes.com!

[ The PC Guide | Troubleshooting and Repair Guide | The Troubleshooting Expert | Troubleshooting Specific Components | Troubleshooting the Motherboard and System Devices | System BIOS ]

I can't seem to enable ROM shadowing, or the system isn't working with ROM shadowing enabled

Explanation: You are trying to enable ROM shadowing in the system BIOS but the system is refusing to boot or behaving unstably when shadowing is turned on.

Diagnosis: Shadowing of the system BIOS works properly in almost every system. Shadowing of the video card usually works. Shadowing of adapter ROMs only works sometimes, depending on the system and on the peripheral. Turning on shadowing may reveal a general problem with the hardware, but usually if shadowing is the only thing causing the problem, the device you are trying to shadow simply isn't designed to work with it. For example, many adapters use both ROM and RAM in their address spaces, and shadowing will cause these to stop functioning altogether.


  • If the device you are trying to shadow is an expansion card, then the card may not allow shadowing. Consult your system documentation. If the device (as well as the system overall) works with shadowing disabled, it is generally better to just not worry about it, as the performance improvement is slight in this case anyway.
  • If the video card will not allow shadowing, this may be a limitation of the video card, though this is uncommon. You may want to diagnose the video card.
  • A failure to shadow the system BIOS ROM can mean a motherboard problem. Troubleshoot it.
  • Any type of problem with shadowing can implicate a memory problem. You may want to troubleshoot the system memory.

Home  -  Search  -  Topics  -  Up

The PC Guide (http://www.PCGuide.com)
Site Version: 2.2.0 - Version Date: April 17, 2001
Copyright 1997-2004 Charles M. Kozierok. All Rights Reserved.

Not responsible for any loss resulting from the use of this site.
Please read the Site Guide before using this material.
Custom Search