Any guide for the procedure ?
I have never used it 

As i said i want to flash my card to previous bios . 
i have save the bios with gpu-z , i have download the NVflash and i need the steps to flash it.

Use It at your own risk
 
-Download the Nflash to Wndows
- Install it
- Copy the file of your old bios to the Nflash directory
-Open the command prompt
- In the commend prompt enter the Nflash diectory
- In the Nflash dirctori enter the next command:
 
nvflash*-4*-5*-6*newbios.rom ( nvflash -4 -5 -6 newbios.rom )
- then restart the PC and check with GPU-Z the bios

If you mean 4B then the just change the ftp link name from 5C to 4B. It's still there available for download. 
 
(pick your own card obviously).

I have the 02G-P4-2678-KR EVGA GeForce GTX 670 FTW with a Motherboard that has a UEFI Bios in it. Do I need to use the UEFI Bios for my card if I am just using Win 7 64bit?

Should I update?
 
I think it is stable, so I don't see a point in doing so.

updated my 670 SC 4gb today worked perfect haven't used it long enough to notice anything yet just played Skyrim for a lil over a hour and ran smooth thanks !!!

I just bought a 670 ftw from amazon. Will it already have this firmware update?

More the likely it will have it. But you can do a easy fast check with the Nvidia control panel.

Q. How can I tell what version I firmware I currently have?
A. There are multiple ways to do this, one way is to right click on desktop and go to NVIDIA control panel. Click on Help, then System Information. Scroll to the bottom of the Details window and it will show your "Video BIOS version". It will be listed as EXAMPLE: 80.04.31.00.72. The numbers in bold identify the version number.

 

William

I just bought a 670 ftw from amazon. Will it already have this firmware update?

Hi All, I would like to disable the CSM in my Asus Z77 mobo, install Windows 8 with secure boot with my new 670 FTW which already has 80.04.5c.00.70.
 
The bios however tells me that the card isn't compatible with UEFI however.  I thought this card bios included this compatibility?
Cheers B