[ASRock] 775Dual Bios / CMOS Bad Checksum error - not battery related

I recently flashed my ASRock 775DualVSTA mobo with a modified BIOS, and now when I boot my PC I get a CMOS Bad Checksum error.

I did some Googling which resulted in me clearing the CMOS for about 15 mins, then bought a new CMOS battery. Neither of these things worked.

When I boot, and I get the CMOS error, I have two options:

1. F1 option of continuing with default settings. When I do this, I get a "NTLDR missing" error which I think is because my Vista is installed on my SATA HD and my BIOS won't recognize this drive as I haven't enabled it in my BIOS (as it's running to the default settings).

2. F2 option of going into my BIOS settings. Doing this, I want to get my BIOS to recognize my SATA drive with my Vista install. By default the BIOS sets the SATA option to RAID and I don't have a RAID setup. So, I switch it to non-RAID, save changes, and reboot. However, just after the POST, I get the same CMOS bad checksum error, meaning I'm back to square one, and a vicious circle.

I wanted to reflash my BIOS, so I created a bootable USB drive with basic DOS and my flash program, but I can't get it to boot from my USB as I think it's looking for my SATA HD, which goes back to the "NTLDR missing" error.

I also looked into getting a bootable CD working, but again I get the "NTLDR missing" error.

Does anyone have any suggestions on how I can get my BIOS reflashed?
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More about asrock 775dual bios cmos checksum error battery related
  1. Welcome to the forums!

    Check the manual on emergency procedures first.
    If the bios chip is removable you can buy a new bios chip from Asrock or else you can RMA the motherboard.
  2. Do you think that my BIOS is messed up?
  3. Yes, you are getting a CMOS Bad Checksum error.
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