HP Compaq BIOS Recovery from a Failed BIOS Flashing Using a USB Flash Disk

The steps to recovery the BIOS are as follows.

1. Format the USB flash disk’s filesystem to FAT16 on another computer.

2. Get the BIOS image from HP’s website (I use F15 version).

Download the BIOS update file from HP’s website (an exe file). Execute the BIOS update file on another computer. It will decompress the files. Select a directory to store the files and you can close the program. In the directory selected, we can get WinFlash.exe. Unzip WinFlash.exe using a program like WinRAR. We can find two .FD files. For my computer and the BIOS version I use, the two files are 306DF15.FD and 306EF15.FD. There are two model for Compaq CQ35 computers, so there are two .FD files. You may try one by one to see which model your computer use. Actually this model can be found in “BIOS Setup” (we can’t start it as the CMOS is bad)

3. Copy the file 306DF15.FD to USB disk’s root directory and rename it to 306D.bin. (the file may be different depending on the model)

4. Remove the AC power and battery from the lapttop.

5. Plug in the USB flash disk to the laptop.

6. Hold two keys: WinKey + B.

7. Plug in the AC power.

8. Hold the Power Button for 5 seconds, then release.

9. Push the Power button as normal to power on the computer.

10. After the laptop starts short beeping, release WinKey+B.

11. The laptop will keep short beeping for about one minute, it will power off itself after recovering the BIOS. If the laptop keeps long beeping or beeping for more than 3 minutes, the recovery fails, possibly because of the wrong image file or the USB flash disk doesn’t work on the laptop. In this case, you may try another image file or another USB flash disk.

Normally power on the laptop after recovering the BIOS and you will see the Compaq logo appearing again.

Disclaimer: I just tested the method in the post with my laptop and am not sure whether it works with one specific model (although it seems work for some others according to the comments). The method in the post is just one example solution. If your data is critical, contact a professional, such as the customer service from HP, to repair it for you.