Bios Boot Block Recovery

If the power went off during the process of updating the BIOS on your Dell Latitude E6400, it can cause the system to become unstable and display an "invalid configuration" error. Here are a few steps you can try to resolve the issue:

1. Try to boot the computer: Turn on the computer and try to boot into the operating system. If it doesn't boot, try to boot into the BIOS by pressing the F2 key repeatedly when the Dell logo appears on the screen.
2. Check the battery: Make sure that the battery is properly connected and has a charge. If the battery is low, it may cause the system to shut off during the BIOS update.
3. Run BIOS recovery: Dell has a BIOS recovery feature that can be used to recover the BIOS in case of corruption. To run the recovery, you will need to create a BIOS recovery USB drive and boot the computer from it. Follow the instructions on the Dell website to create the recovery drive and run the recovery process.
4. Try a different power source: If you were using a battery during the update, try using the AC adapter instead. If you were using the AC adapter, try using a different one, or a different outlet to make sure that the power supply is stable.
5. Take to a repair shop: If the above steps do not work, it may be best to take the computer to a repair shop for further diagnosis.

It's important to note that running a BIOS recovery may cause you to lose all data on your computer, please make sure to backup your data before proceeding.

Take disk out. Power down. Restart. See if will start up without a disk in it. Might be confused by your disk. Did you try to F8 or F9 while restarting to get into BIOS (trying to remember which one will boot you to BIOS). Then see if the CD/DVD was disable for boot up. Turn that back on if you can get into BOS so it will boot up you recovery disk.. If your OS is completely gone, you will have to reinstall...

According to my troubleshooting manual of Acer Aspire 4520-Z3 about

BIOS Flash Utility:

The BIOS flash memory update is required for the following conditions:
New versions of system programs
New features or options
Restore a BIOS when it becomes corrupted.

Use the Phlash utility to update the system BIOS flash ROM.
NOTE:
If you do not have a crisis recovery diskette at hand, then you should
create a Crisis Recovery Diskette before you use the Phlash utility.
Do not install memory-related drivers (XMS, EMS, DPMI) when you use the Phlash.
Please use the AC adaptor power supply when you run the Phlash utility.
If the battery pack does not contain enough power to finish BIOS flash,
you may not boot the system because the BIOS is not completely loaded.

Follow the steps below to run the Phlash.
1. Prepare a bootable diskette.
2. Copy the flash utilities to the bootable diskette.
3. Then boot the system from the bootable diskette.

The flash utility has auto-execution function.
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You need to prepare a bootable Flashdisk into dos mode
then you should search for the above mentioned crisis recovery
diskett and transfer its content to the flashdisk.

I read from another forum that for recovery of Aspire 4520 problem
can be done through pressing of the keys combination as follows:
press FN + ESC and hold them, then just hit the power on button
and release it, after awhile "the power button" should blink red,
release the keys FN+ESC and don't touch anything.

After successful of recover the bios it should restart normally.
That happen after 20-30 minutes. If it doesn't restart just repeat the
process.

Hope it helps

You need to repair your windows system files.
for that insert windows disk or recovery disk into cd /dvd rom then when you power up the computer press F1 or F2 or del or ALT+F2 key to enter in bios then you can see bios configuration page then go to boot menu and set first boot device as cd/dvd rom then save settings and exit from bios .
then it boot with disk follow the procedure on screen then first choose recovery console then type in console "chkdsk /r" it fix and recovers error on harddrive.
Then restart computer then again boot and this time choose R for "Repair previous windows" then it repair it then you can use your windows again.
Let me know if you need further assistance.
Thanks for using FixYa.

unfortunately, if the BIOS lost its firmware you must send it to the vendor to replace the BIOS chip

Solution 1: Boot-block BIOS
Modern motherboards have a boot-block BIOS. This is small area of the BIOS that doesn't get overwritten when you flash a BIOS. The boot-block BIOS only has support for the floppy drive.If you have a PCI video card,you won't see anything on the screen because the boot-block BIOs only supports an ISA videocard.
Award: The boot-block BIOS will execute an AUTOEXEC.BAT file on a bootable diskette. Copy an Award flasher & the correct BIOS *.bin file on the floppy and execute it automaticly by putting awdflash *.bin in the AUTOEXEC.BAT file.
AMI: The AMI boot-block BIOS will look for a AMIBOOT.ROM file on a diskette. Copy and rename the correct BIOS file on the floppy and power up the PC. The floppy doesn't need to be bootable. You will see the PC read the floppy, after about 4 minutes you will hear 4 beeps, this means the transfer is done. Reboot the PC and modify the CMOS for your configuration.
Solution 2: Get a new BIOS chip

1. Contact your motherboard manufacturer to see if they sell BIOS chips. Some motherboard manufactures send them for free.
2. Contact a company that sells pre-flashed chips, like Unicore Software, FlashBIOS.ORG, BadFlash or Bios World

Solution 3: Hot-swapping
Note: I'm not responsible for any damage this method may do to you or your computer !

1. Replace the corrupt chip by a working one. The best option is to take the working BIOS chip from a motherboard which has the same chipset although that's not absolutely necessary. It just has to give you a chance of booting into DOS. Before pulling the working BIOS chip out of it's original motherboard, set the System BIOS cacheable option in the BIOS to enabled.
2. After you have put the working BIOS in the motherboard with the corrupt BIOS boot the system to DOS (with a floppy or HD).
3. Now replace (while the computer is powered on) the working BIOS chip with the corrupt one.
4. Flash an appropriate BIOS to the corrupt BIOS and reboot.

Solution 4: (for Intel motherboards)

1. Change Flash Recovery jumper to the recovery mode position (not all products have this feature)
2. Install the bootable upgrade diskette into drive A:
3. Reboot the system
4. Because of the small amount of code available in the non-erasable boot block area, no video is available to direct the procedure. The procedure can be monitored by listening to the speaker and looking at the floppy drive LED. When the system beeps and the floppy drive LED is lit, the system is copying the recovery code into the FLASH device. As soon as the drive LED goes off, the recovery is complete.
5. Turn the system off
6. Change the Flash Recovery jumper back to the default position
7. Leave the upgrade floppy in drive A: and turn the system on
8. Continue with the original upgrade

The Boot Block

The preceding section discusses updating the program code in the system BIOS by flashing it (replacing it under software control). If the flash procedure is done improperly, the BIOS code can become corrupted, which will cause the system to go into an unbootable state. Many newer systems come with a feature where a 4 KB "boot block" program is included as part of the BIOS. This is a tiny piece of code whose job it is to recover from a situation where the BIOS code is incorrect or corrupted.

If your motherboard supports this feature, when the PC tries to boot and finds the BIOS code corrupted, the boot block will try to recover the BIOS code, usually by reading it from a specially-prepared floppy disk. You may have to change a jumper on the motherboard to enable this capability, and you may need to make use of a "plain vanilla" ISA video card. The boot block will load the BIOS code and then when you next reboot, the regular BIOS code should be in place and the problem resolved.

You will need to follow the special recovery procedure outlined by your motherboard manufacturer if you want to take advantage of this feature.

It depends on what bios the machine has, there are recovery procedures, atleast on laptop bioses. That when a set of keys is pressed it reads the bios image from a floppy or from a usb stick / cd and flashes the bios automatically.

Look online for Bios recovery (find out what bios you have, ami, phoenix, etc and then look for _____ bios recovery)

Solution 1: Boot-block BIOS
Modern motherboards have a boot-block BIOS. This is small area of the BIOS that doesn't get overwritten when you flash a BIOS. The boot-block BIOS only has support for the floppy drive. If you have a PCI video card you won't see anything on the screen because the boot-block BIOS only supports an ISA videocard.
Award: The boot-block BIOS will execute an AUTOEXEC.BAT file on a bootable diskette. Copy an Award flasher & the correct BIOS *.bin file on the floppy and execute it automaticly by putting awdflash *.bin in the AUTOEXEC.BAT file.
AMI: The AMI boot-block BIOS will look for a AMIBOOT.ROM file on a diskette. Copy and rename the correct BIOS file on the floppy and power up the PC. The floppy doesn't need to be bootable. You will see the PC read the floppy, after about 4 minutes you will hear 4 beeps, this means the transfer is done. Reboot the PC and modify the CMOS for your configuration.
Solution 2: Get a new BIOS chip
Contact your motherboard manufacturer to see if they sell BIOS chips. Some motherboard manufacturers send them for free.
Contact a company that sells pre-flashed chips, like Unicore Software, FlashBIOS.ORG, BadFlash or BiosWorld
Solution 3: Hot-swapping
Note: I'm not responsible for any damage this method may do to you or your computer !
Replace the corrupt chip by a working one. The best option is to take the working BIOS chip from a motherboard which has the same chipset although that's not absolutely necessary. It just has to give you a chance of booting into DOS. Before pulling the working BIOS chip out of it's original motherboard, set the System BIOS cacheable option in the BIOS to enabled.
After you have put the working BIOS in the motherboard with the corrupt BIOS boot the system to DOS (with a floppy or HD).
Now replace (while the computer is powered on) the working BIOS chip with the corrupt one.
Flash an appropriate BIOS to the corrupt BIOS and reboot.
Note: Use a flasher from MRBIOS. They are known to work best. You can find them at ftp://ftp.mrbios.com
Solution 4: (for Intel motherboards)
Change Flash Recovery jumper to the recovery mode position (not all products have this feature)
Install the bootable upgrade diskette into drive A:
Reboot the system
Because of the small amount of code available in the non-erasable boot block area, no video is available to direct the procedure. The procedure can be monitored by listening to the speaker and looking at the floppy drive LED. When the system beeps and the floppy drive LED is lit, the system is copying the recovery code into the FLASH device. As soon as the drive LED goes off, the recovery is complete.
Turn the system off
Change the Flash Recovery jumper back to the default position
Leave the upgrade floppy in drive A: and turn the system on
Continue with the original upgrade

Flash Recovery-Config Some motherboard makers incorporate a flash recovery-config jumper or boot block recovery jumper on their motherboards. This can often be used to recover from a bad or failed flash. On most machines a small segment of the flash ROM does not get overwritten when you perform a normal flash update. This small portion of code contains a basic boot block which can enable the machine to reload another BIOS from floppy disk.
If you have a laptop or desktop without a floppy. You can either fit a floppy in the conventional manner or in some cases a USB floppy or CD-ROM can be used.