Desktop Operating Systems and Recovery

I need help updating the BIOS on my HP dc7800 CMT. I keep getting this error:

The system BIOS updte file (C:\Users\f\Downloads\ROM.CAB) is missing or corrupt. The system BIOS will not be updated.

I tried to update using the sp53611.exe (8.0 MB) 1.32 Rev. A(6 Dec 2011) HP Compaq Business Desktop System BIOS (786F1 BIOS)

Which can be found here.

http://h20564.www2.hp.com/hpsc/swd/public/detail?sp4ts.oid=3459243&swItemId=vc_97114_1&swEnvOid=4059

The current version of my BIOS is: 786F1 v01.04 7/18/2007

I am running Windows 7 64-bit  Ultiate. I noticed on the page for the software (linked to above), it mentions most flavors of Windows 7 64 bit, but it DOESN'T mention Win 7 ULTIMATE 64-pit.

Here is what I did:

1) Restarted computer in safe mode

2) Logged in as administrator

3) Started task manager to make sure all apps and most services were stopped

3A ) as an extra precaustion, I even stopped Windows Defeneder

4) Double clicked sp53611.exe and let it install software.

5) This opened a web page. I clicked on the link that was under the Update Bio from a windows environment.

6) The process started, but then I got the error above.

Any ideas on what to do next?

Is it possible that the BIOS CAN'T be updated because the software doesn't support windows 7 64-bit ULTIMATE???

Thank you in advance. I have a new graphics card coming today (Radeon HD 6570 - which was recommended by Mr. Paul Tikkanen, Thank You), and I guess that I should have my BIOS somewhat current, right?