I have (intentionally) killed my card MANY times and brought it back to life with these various methods...

When flashing rom's from image cd's uploaded by forum users you can never be sure of the integrity of the files that the cd contains. You may use other preset roms or make your own roms, but you still have the potential to compromise the display ability of your card. If after flashing, on bootup, your screen remains blank but the computer is on then you flashed a corrupted bios for your card. In such instances, it will be necessary to blind flash your card back to stock/working condition.

IMPORTANT: I recommend you try the flash drive method first and foremost, however, I think I have fixed any problems with the boot cd method

The -4 -5 -6 command arguments will be referred to as force flashing. This bypasses certain safety limitations built into nvflash.

The -A command argument will be referred to as auto flashing

Boot Priority
How are you certain that the device you want to be booted is being booted without a screen to look at?
Typically, on our notebooks, the default bios settings do not give any device's boot priority ahead of the HD (these devices include usb, cd, etc). This can be a problem when trying to flash your card in DOS and not being able to see the screen. One resolution is either changing the boot sequence (F2 on startup) or performing a selective boot (F12 on startup) to boot from a device other than the HD. But chances are, if you are reading this guide, then this information is after the fact. As you can imagine, this is a little more difficult to do without a screen output to look at. So the easiest way to resolve this is to just remove the HD (only takes two screws typically). Along with this, however, you want to remove all storage media that YOU ARE NOT TRYING TO BOOT FROM as well. This includes cd's, dvd's, flash drives, sd cards, usb massager (jk), etc

Note A: Actually, the floppy drive, as is typical with many bios's, has a boot priority ahead of the HD but who uses those anyway?
Note B: If you insist on not removing your HD, then I will address this in the next post but be aware that removing the HD is much simpler. All proceeding instructions within this post will assume that the HD will not be booted prior to the bootable device containing nvflash (The next post does not exist yet but I will put it up later once I do some reorganizing)


Bootmethods - Bootable USB and Bootable CD
Both of these methods are relatively modern and readily available on most machines

Creating a Bootable USB drive
There are a variety of ways to make your usb drive bootable but the easiest method is HP's USB disk storage format tool...It works with most flashdrives...
CAUTION: This will delete any data currently on the flash drive
Download it here
Install it
Download these dos files
Extract these to a folder name "dosfiles" (anywhere you want: my documents, desktop, etc)
Run the program(HP USB format tool) and check the "create a dos startup disk box"...
Then use "using files located at..." and browse to the dosfiles folder you created...
It will format and then you can put whatever executables or regular files you want on it...
Your USB drive is now bootable and contains everything you need to flash the GPU (if you just came here to make a bootable USB you can stop now)
Download any version of nvflash that supports your gpu...
Extract the files...there will be three files (usually)...you can delete the info (text document) and put the "nvflash" and "cwsdpmi" executables on your flash drive in the root directory
Also put any rom files you want here in the same directory (root)...
To run a command automatically at bootup of usb, you need an autoexec.bat
To create the autoexec.bat create a textfile on your flash drive (ex. blah.txt)
Open it up and insert the following command in it 'nvflash -4 -5 -6 [romname].rom' (see fully automated flashing section below for different commands)
Save it as 'autoexec.bat'
The autoexec.bat automatically carries out the provided command at bootup from usb...

Note: You may have the option to hide known file extensions enabled in which case you would need to disable to create the autoexec as a batch file instead of a txt. Alternatively use the command line and change to the directory with the 'cd' command. Then use the rename command. For example, 'rename autoexec.bat.txt autoexec.bat' . The file icon indicates what type of file it is in case you are unsure.

Creating a Bootable CD
Again there are a variety of methods but I prefer Bart's Method
You can follow the directions from his site...
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IMPORTANT: If you have over 2 GB of RAM installed in your system read here. If not, then skip this part. If you are lazy and you have more than 2 GB of RAM you can just install 2 GB of RAM or less and skip this part too
Once you have extracted all the files to their locations, you need to modify some things to support more than 2 GB of RAM
Download these files extract them to your Desktop
Replace C:\bcd\disk1\autoexec.bat with the one linked in the memfiles archive
Replace C:\bcd\os\md701\bin\himem.sys with the one linked in the memfiles archive
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Download any version of nvflash that supports your gpu...
Extract the files...there will be three files (usually)...you can delete the info (text document) and keep the "nvflash" and "cwsdpmi" executables
Put any files you wish to have on the cd in the 'cds\cdromsi\files\' directory...(rom's, nvflash, etc)
Make sure you have the 2 files from the extracted nvflash (you can delete the text document) in this directory as well as a working copy of your videocard rom
Your CD now contains everything you need to flash the GPU (if you just came here to make a bootable CD you can skip down to after the red NOTE)
Edit the autorun.bat in this directory (right click and select edit)
Do not delete anything currently stored in the autorun file...
Make a newline at the end and use the following command 'nvflash -4 -5 -6 [romname].rom' (see fully automated flashing section below for different commands)
The autorun.bat automatically carries out the provided command at bootup from cd...

Note: You may have the option to hide known file extensions enabled in which case you would need to disable to create the autoexec as a batch file instead of a txt. Alternatively use the command line and change to the directory with the 'cd' command. Then use the rename command. For example, 'rename autoexec.bat.txt autoexec.bat' . The file icon indicates what type of file it is in case you are unsure.

By default this cd will run in max compatibility...
I have read that nvflash needs to be used in clean dos (i.e. no memory expansions). This, however, is contradictory to the next line. I will test this later.
NOTE: For the 7900 series gpus, apparently it needs to boot in max memmory. To change this edit the file C:\bcd\os\md701\config.sys. Open it with notepad and set menudefault from 'AUTO' to 'MAX'. Save the changes...
Now open the command prompt and change the directory to the bcd folder with the cd command (cd "c:\bcd" for example)...
Use the command 'bcd cdromsi' to write to a blank cd...


NvFlash - Fully Automated Setup
This section is only for those who wish to carry out this process with as little guessing and user-input as possible.
IMPORTANT: If you wish to use this section you must use an older version of nvflash (5.31) attached here
Note that this version will only support 7 series gpu's and below...
It includes some nice featues that nvidia decided to remove in later versions
In particular, using this version of nvflash means you can use -A switch for automatic flashing without confirmation prompts (in most cases)

Command Line
If you wish for the process to be fully automated (you typically would) without your intervention you must use the -A switch as well
ex. 'nvflash -4 -5 -6 -A [romname].rom'

At any rate use -A and you can just boot up and the autoexec will do everything...
You will only have to press Ctrl+Alt+Delete to Reboot after the flash has carried out

Command Line Extended
The -y switch automatically restarts the computer after the flash has taken place
This allows the user to know that the command has run through error-free upon reboot
So, Use 'nvflash -4 -5 -6 -A -y [romname].rom' to restart the computer automatically after flashing...
This is sweet because you dont have to do anything...

If you use the -y switch and leave your computer be, this will result in an infinite loop until you remove the boot media


Flashing the BIOS
Insert the cd or usb and then boot the laptop...the autoexec/autorun will handle most of the job...
The numlock indicates that the computer has booted and is preparing to boot a certain device (HD partition, flash drive, etc)
You should see the led of num lock...if you don't wait...
Just wait a min (be patient) for the autoexec/autorun to carry out its routine...the autoexec/autorun will not timeout on you
If you did not include the -A switch you must wait until you think the command has been run and then press 'y' 2-3 times to confirm the flash. Usually the led's (numlock, capslock, scroll-lock) cycle and then stop and the system beeps singly two times to indicate that the card has been flashed
If you did not include the -y switch you must wait until the bios has been flashed and press 'ctrl+alt+del' to reboot
If you did include the aforementioned switches (-A and -y), just sit back and relax

Hopefully you can see your screen


Telltale signs
This is mostly useful for when you are not immediately seeing your numlock key...
Your numlock will turn on before any device is booted but it may be quite awhile after the numlock turns on that the device boots
Hearing your cd drive load and flicker its led or seeing your usb drive's led (if it has one) flicker and remain either off or on are telltale signs that the autorun is carrying out/has carried out and is waiting on you to press 'y'
Do not confuse this with normal bootup routine...Your flash drive will most likely flicker once right as you press the power button...Your cd drive will load on startup but it will then stop loading...If after the device (flash drive or cd drive) stops its initial load you hear it start loading again (in the case of cd) and/or see the led flickering then this is the sign (for cd or usb)...

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If you wish to make your own backup of your current rom download
NiBiTor 5.0

You can also use the -b switch with nvflash to backup your bios if you didn't do so with NiBiTor. Here is the latest nvflash that should be compatible with newer eeprom's:
nVFlash 5.72

Both of these links are auto-updating links so they should always be fairly new
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Notes
Make sure the rom you include in your autorun/autoexec is a stock rom or at least a rom youre 100% confident in...
The -4 -5 -6 command switches for nvflash are not recommended for typical use...this is just to make sure nvflash doesn't give you any nagging and all you have to do is press 'y'
I am aware that I dont type in complete sentences...
Secondary GPU - (note to self) Expand on this
It is a good idea to use piping to figure out whats going on with the computer without being able to see the screen
It took me 1h 30 min to recover my gpu one time. All I had to do was wait for the bios to initiate (1 hr) and boot my flash drive (30 min) and press 'y'...dont give up too quickly...
Pressing buttons prematurely can interrupt the autoexec, particularly for cd method
Make sure the name of the romfile is under 8 characters...
Sometimes your card is just broken, no matter what you do...
I am unsure why people have reported having to usethe max memory option to flash the 7900 series since apparently it doesnt even support emm386
This guide is only about blind flashing a card with a corrupt EEPROM. For other GPU faults, this guide is not applicable.

This guide is best viewed in old style forum layout.
This is a software-based guide. If you need help with the hardware aspect of blind flashing you can ask me questions but I will be less useful.