Recently I am unable to access my Bios. The Motherboard Manufacturer screen hangs for a long period of time then posts whereby I see that a Promise Raid controller (I don't use raid) cannot find anything attached and Bios is not installed. Later I see a Bad checksum. (Keyboard is dead at this point and cannot get into Bios). It will eventually boot into windows. Note that I cannot use CDRW and DVD-ROM which stopped reading or booting into for the last month. Tried plugging USB keyboard w/adapter into PS2 connection (It will not even activate in windows). I have been working with other techs to fix CDRW/DVDRom issue (They open and close and appear to burn to CD but will not verify/read CDs

the article here should explain the most likely causes.

Cannot access BIOs!!!

Did you try any of the other suggested fixes?

Replace the battery for the bios. A low battery can account for the checksum error.

What make system/motherboard do you have? How old is the system/motherboard?

Reset the bios via the jumper on the motherboard. Consult the motherboard's users manual.

Scan the system with your virus software. Make sure that you have the latest virus definitions for the virus software that you are using.

If the bios settings have been corrupted, use a ps2 keyboard and see if you can get into the bios. if you are using a usb keyboard, the usb keyboard settings may have been turned off in the bios due to the corruption. Settings in the bios being corrupted may also explain why the optical drives are not recognized.