BIOS or DOS ROM checksum error

[RDick111]

Hello,
When I start desktop HP Pavilion a1250n
XP Media Center Pro, I get a black screen with ROM checksum error: (the first part of the ROM is off the edge of the screen so I can't tell if it's DOS or BIOS, all I see is "OS ROM checksum error")
detect floppy Drive A: trying to boot from it...boot failed; etc. etc.

This puzzles me as I do not have a floppy drive. I've always had to shut down improperly to get out of that halt, being unable to boot. Then when it does boot properly, the images on the screen jerk uncontrollably back and forth, so I restart and it boots correctly. So it seems. but I've also had CD DVD writing problems and program crashes during a burn.

Could these issues be related somehow? Sorry, but I'm not all that knowledgeable, but have searched and researched for a solution; I just don't know enough to troubleshoot correctly. Can you please guide me along?

 

[treefrog07]

You may need another battery for the motherboard, has the system prompted you to set the date and time at boot?

You could also try resetting the BIOS. Unplug the system from the wall, remove the left side panel as you are looking at the front of the box. Look at the motherboard and find a small plastic jumper on a set of 3 pins - the 3-pins should have white printing underneath that show "CLR_CMOS" without the quotes. Remove the jumper and connect it to the middle pin and the pin that was exposed before you removed the jumper. Leave it there for about 30 seconds, then re-place it on the two pins it was on originally. Replace the side cover. Plug the cord into the wall, and power-on your system.