The Janitor's bird, Miguel, eats Barbie.

Please be aware that this page was originally written to recover from the BootBlock BIOS on Abit motherboards.  This information may be applicable to other manufacturers with code built on Award's 6.00 BIOS.  Also be aware that I no longer build desktop systems and, consequently, cannot maintain these procedures without feedback from people who actually use them.  Messages may be left on my Guestbook.

Once in a while a BIOS flash fails or, for any number of other reasons, your BIOS becomes corrupt, you will find that your system will not boot.  With newer BIOS releases you may receive a screen that the AWARD BootBlock BIOS is attempting recovery and that it's searching for a diskette. For example:

Award BootBlock BIOS v1.0
Copyright (c) xxxx, Award Software, Inc.

BIOS ROM checksum error

Detecting floppy drive A media...

With older BIOS' (and at other times) your system will appear to be dead, with the exception that it will attempt to boot from the diskette drive and then hang.

In the above scenarios, your BIOS is corrupt and the system is attempting to read the floppy.  In these cases the BootBlock is attempting to recover your BIOS.  The BootBlock is the last block of the BIOS code, which will attempt to boot if the main BIOS code has been corrupted, enabling you to boot from a floppy to reflash.  Sometimes it works, sometimes it doesn't.

I generally don't recommend reprogramming the BootBlock when you flash your BIOS, because you risk losing your only insurance against a failed flash.  Award's BootBlock code hasn't changed in years.

One exception to this rule: some boards have BIOS code so large that it extends into the space reserved for the BootBlock code.  In order to flash these boards, it's necessary to include the /WB switch (write BootBlock).

If you have funky stuff going on, like missing options on some of the setup menus, after recovering, reflash your BIOS including the /WB switch in the command line for AWDFLASH.EXE.

In order to attempt the reflash, prepare a DOS boot diskette with no CONFIG.SYS.  If you prepare a boot diskette in Windows, CONFIG.SYS may be hidden by default, so it will be necessary to change your Folder Options/View settings in order to see it (show hidden and system files and do not hide protected and operating system files).

Newer boards will require much more space on the diskette than was previously needed for the flash due to ever increasing BIOS image sizes.  Because of this, remove everything on the diskette except IO.SYS, MSDOS.SYS and COMMAND.COM (these three are the only files necessary to boot to DOS).  Again, you may need to adjust your "View" settings in order to see everything on the diskette.

Download the latest BIOS for your board and unpack it into a work directory on another system's hard disk.  You'll get as many as five files.  The two you are interested in are named xxxxxx.BIN (replace xxxxxx with the name of the BIOS .BIN file that you are attempting to flash) and AWDFLASH.EXE.  Copy these two files to your DOS diskette.

For Beta BIOS', download the BIOS image and change its file extension to .BIN.  Download the latest "gold" release for your board to get the appropriate version of AWDFLASH.EXE.

Always ensure that you use the correct version of AWDFLASH.EXE!  Phoenix/Award regularly updates AWDFLASH.EXE program to support ever-changing hardware.

I've been accused of being a little vague here... this DOS Dinosaur needs to be mindful that many out there aren't familiar with DOS command line utilities.

CONFIG.SYS is a text file that is parsed just as DOS starts up.  This file is used to load device drivers and memory management code.  AWDFLASH.EXE may have problems if anything gets loaded into memory from CONFIG.SYS so the best way to avoid this problem is to ensure that the file doesn't exist or is empty.

AUTOEXEC.BAT is a text file that is parsed just before you are dumped at the command line when DOS boots.  This file allows you to run commands.  It's necessary to create an AUTOEXEC.BAT file to recover with the BootBlock BIOS because your keyboard will not be functional.  Your monitor may not display anything either .. you may be running BLIND

To create AUTOEXEC.BAT, create a new text file on the diskette with NOTEPAD.  Don't use WORDPAD or any other word processor .. you want plain text.

Type the following command exactly as presented below in the first line of the file and press ENTER.  Type nothing else.  Click FILE then SAVE AS then type A:\AUTOEXEC.TXT (NOTEPAD doesn't easily allow any other file extension).  Exit NOTEPAD.  Navigate to your diskette drive in Windows Explorer.  Right-click on AUTOEXEC.TXT and select RENAME from the context menu.  Type AUTOEXEC.BAT and you're done.

Following is the command line you want:


Note the spaces after .EXE and .BIN and before each "/" in the above command.  Replace "xxxxxxxx" with the name of the BIOS .BIN file.

Prior to flashing with your recovery diskette, remove the power cord and open up your computer (you're going to need to crack the case after the flash anyway in order to manually clear your CMOS).  Disconnect all drives, except your floppy drive.  Manually clear the CMOS memory using the steps outlined below.

Remove the main power cord
Remove the motherboard battery (optional)
Move the Clear CMOS jumper (CCMOS1 on Abit boards) from pins 1 and 2 to pins 2 and 3
Press your power switch several times to discharge any remaining power from the motherboard
Wait a minute or two
Replace the motherboard battery (if you removed it)
Move the Clear CMOS jumper back to pins 1 and 2
Reconnect your drives
Close up the case
Restore the power

Several users have reported back that they were only able to recover from the BootBlock after disconnecting everything except the floppy drive and forcing the system to Failsafe Defaults by clearing the CMOS.

To flash with this diskette, place the floppy in drive A:, power up your system and (hopefully) after several minutes your system should reboot itself.

You should see what's happening on the screen with newer motherboards.  With many older boards, you will be running "blind" unless you have an ISA Video Card installed in your system.

If the BootBlock is going to work you'll see activity on the diskette while DOS boots, then a short pause, followed by more activity while AWDFLASH.EXE is loaded.  After a few moments, the BIOS .bin file will be parsed by AWDFLASH.EXE and the blocks of your BIOS chip will be written (there will be periods of time when nothing appears to be happening .. this is when the BIOS blocks are actually being written).  The /R switch will force the system to reboot when the flash is complete.

When your system reboots, wait until you see the POST screen.  You'll get a CMOS Checksum Error at this point, because the switches we included in Autoexec.bat clear your CMOS to Failsafe Defaults.  Turn off the system using the switch on the PSU.

Because some BIOS' complete their "save" while the system is rebooting, wait until you get to the POST/CMOS Checksum Error before turning the system off.

Because your BIOS settings and many tables are stored in CMOS memory, and not everything will clear using the switches included above, you should manually clear the CMOS memory again.

When you restart, you'll get another CMOS Checksum Error at the POST screen.  Press DEL and reprogram your BIOS.  Start with the selection of Load Optimized Defaults from the main menu.  If you need to adjust the voltage for your RAM in order to run your system, make that change next.  Remove the diskette (you might boot to it again and run the flash all over).

When finished programming your BIOS, press F10 to Save and Exit.  Your system will reboot and you'll be good as new.

If nothing happens and your floppy doesn't start to access after a few minutes, power down and try again - sometimes it takes several attempts to force the BootBlock to start running the flash.

The AWDFLASH.EXE command modifiers used above are:

/CC = clear CMOS data after programming
/CD = clear DMI data after programming
/CP = clear PnP (ESCD) data after programming
/QI = use BIOS I.D. string from BIOS .bin file
/R  = reset system after programming
/PY = program flash memory
/SN = don't save existing BIOS

To view all of the modifiers for AWDFLASH.EXE, type the following at a DOS prompt:


Good luck with your BIOS Recovery.


If you cannot get the BootBlock to flash, your chip may be too corrupt to recover - following are some options

Pay a visit to and order a replacement chip.  You'll have to provide the BIOS version you want flashed to a chip.  Their service and shipping usually are pretty quick.  They offer international service and their price is fairly reasonable.

Pay a visit to and order a replacement chip.  Their service and shipping are usually pretty quick.  They offer international service and their price is fairly reasonable.

Get it reflashed locally

Call around to an electronics store or computer builder shop in your area and ask if they have an EEEPROM burner (with a PLCC adaptor if you have a PLCC chip).  You'll want to peel off the BIOS chip label in advance and copy the numbers printed on the chip down.  You'll also need to ask if they can flash your specific chip.  I've had a corrupt chip reflashed by a local shop for US$5.00 (plus the cost of a chip, if I wanted one).

Hot Flash

If you have a friend with the same motherboard or one that uses the same or a plug compatible BIOS chip, you may be able to "Hot Flash" your chip using your friend's motherboard.  To do this you prepare your BIOS flash diskette as indicated above EXCEPT you do not include the AUTOEXEC.BAT file (you do not want this diskette to "auto-run" on your friend's computer or you may owe him or her a new BIOS chip as well!).

A chip-puller tool is recommend for Hot-Flashing.

If you don't have a chip puller tool, you can fashion one by straightening a paper clip and making a small bend at one end.

On two opposite sides of the PLCC socket is a small opening where the chip puller or straightened paper clip is inserted.  If using a paper clip, ensure that your bend at the end will fit into the socket and under the BIOS chip like a small hook.

When using a chip puller tool, insert the ends of the tool into the openings on the socket and gently squeeze the tool to extract the chip.

When using a straightened paper clip, work alternating from one corner to the other, inserting the paper clip into the opening and gently pull up on the chip.  Do not attempt to pull the chip all the way out on one corner because you will risk bending the pins on the chip or damaging the socket.  Instead, alternate from one corner to the other, pulling up a small bit each time until the chip pops up from the board.

Before beginning with this process, it's imperative that you know the correct orientation of the BIOS chip in your board and your friend's board.  PLCC chips have one corner that has been cut.  This cut mates exactly to the PLCC socket on the motherboard.  Also, if you peel any labels off the top of the chip, you'll see that there is a dot on one side of the chip that mates to a matching dot on the socket.

Know and remember your chip orientation.  Mess up and you fry the chip .. this is the most common mistake when swapping out a BIOS chip, so take care.

Because you will be working on a running system, remove the chip from your friend's system beforehand.  On both your chip and your friend's chip, tie dental floss or fishing line (both non-conductive) diagonally on the chip on the non-cut corners (mating to the extractor tool insertion openings).  Tie the knot on the top and leave tails long enough that you can grasp them easily while the system is running.  Do not leave tails so long that you risk having them caught up by a running fan.

Gently reinstall your friend's chip.  Do not push it all the way in; simply ensure that you've pushed it in far enough that all the pins make positive contact with the socket and you can easily pull the chip up while the system is running.  You may want to practice prior to starting up your friend's system.

Boot your friend's system with your BIOS flash diskette.  When you reach the DOS "A>" prompt, gently remove the chip from your friend's motherboard and replace it with your chip.  Take extra care that you do not bend any of the pins on the chip.  Carefully insert your corrupted chip, aligning the chip in the same manner as the chip you removed.

Flash your chip using the command:


Do not include any of the other switches in the command lines described above.  You do not want your friend's computer to automatically reboot after the flash, nor do you want to clear your friend's CMOS memory.  When Awdflash finishes and you get the F1/F10 reboot or exit message, turn off your friend's system using the switch on the PSU.  You do not want to reboot your chip on your friend's system unless it's exactly the same model and revision motherboard.

Remove any dental floss or fishing line from both chips.  Replace your friend's chip and then replace your own chip in your system.

Continue with the above instructions to manually clear your CMOS settings in order to complete your recovery.

BIOS Savior

This has nothing to do with recovering your currently corrupted BIOS .. but it does buy you insurance that you won't have to go through this again.

Pay a visit to and look into a BIOS Savior kit for your motherboard.  Sourcing information for several countries appears on their website and the price is fairly reasonable.

A BIOS Savior is a little daughter card that plugs in place of your BIOS chip, with your chip plugged on top "piggyback" style.  You boot your system with your existing BIOS and then flash the daughter card BIOS by flipping a switch installed on the the back of your system case.

This provides you with a backup copy of your BIOS and lets you try out new or beta BIOS revisions without risking corruption.  You'll never have to visit this page (and risk going blind) ever again!

The BIOS Savior kit includes a chip puller tool.

Most vendors do not pre-flash the BIOS Savior before shipping, so this is probably not a solution to a dead BIOS.  But it's nifty insurance for the future.

NF7-S revision 2.0 boned with NF7-S2 / NF7-S2G BIOS

While the stated purpose of this page is to recover from the BootBlock BIOS, many have been referred here in hopes of recovering their Abit NF7-S revision 2.0 board when they've wrongly flashed the code for the NF7-S2 / NF7-S2G.

Abit forum member cloudy1 posted the following :

I also wrongly flashed my NF7-S v2 motherboard with the NF7-S2 BIOS.

I tried to reflash the proper BIOS, but AWDFLASH 8.23K didn't work -- It failed with a "It is not Award BIOS" error -- even with a /F switch.

With AWDFLASH 8.33A and 8.54B, I was able to get a little further.  However, both failed with the following error:

Programming Flash Memory -

Flash ROM is Write-Protected
Please make sure whether lockout jumpers
is set to correct or not.

Warning: Program Chip fail !

Finally I tried the /QI command and this worked, with the BIOS restored to the proper version.

The command i used was :


I hope this saves others from having to buy a new Flash Rom chip or servicing fees.

Thank you cloudy1 for providing this information!