0251 error on my older computer

[ViviTheMage]

It's a p4 1.5ghz, with 256mb ram and I am just trying to load her back up, I had removed it from its origonal COMPAQ case, into another case that has more drive bays and easier access to everything then those dang compaqs, but everytime I try to boot I get 0251 - cmos error -- default settings have been enabled, and I have no way of getting into bios still, or anything of the sort. I do not know the name brand of the motherboard, nor are there any distinctive numbers/names on it, I have googled all number strings and nothing has come up.

I can get my hard drive to reformat fine, it boots strait to CD, but it wont boot to HD , which is what I need it to do to complete me OS install.

Any thoughts ?

 

[ViviTheMage]

while holding ESC and DEL down I can get into bios, finaly, and both the cd drive and HD are on the same IDE channel.
both are detacted, the HD is formated, but it still wont boot to the HD, nor will it stop the checksum error.