System requirements:
  • Power supply
  • USB storage formatted to FAT16, FAT32 or NTFS
  • ASUS X99 motherboard featuring USB BIOS Flashback®

Click below model or visit ASUS official site at to download and extract the
latest BIOS CAP file.

  • BIOS version
  • 0904 or later
  • 0904 or later
  • 0401 or later
  • 0402 or later
  • 0603 or later

Rename the file as below table, and then save it to the USB storage device’s root directory.

  • Model name
  • X99-DELUXE
  • X99-S
  • X99-PRO
  • X99-A
  • Rename the file
  • X99D.CAP
  • X99S.CAP
  • X99P.CAP
  • X99A.CAP
  • R5E.CAP

Refer to your user manual to make sure the USB port that support USB BIOS Flashback®, and plug the USB storage device to the specific USB port. Then press the USB BIOS Flashback® button/ROG Connect button for three seconds till the LED begins to blink, then release.

Connect to a power supply

Wait till the LED stops blinking, indicating that BIOS flashing has been completed

Check this video guide


  1. Do not unplug the portable storage device, power the system down, or press the CLR_CMOS button while BIOS updating is ongoing, or the update will be interrupted. In case of interruption, follow the recommended procedures again to complete the BIOS update.
  2. If the light flashes for five seconds and turns stable, USB BIOS Flashback® is not operating properly. This may be caused by improper installation of the portable storage device, an error in the file name, or incompatibility in file formats. If this is the case, restart the system until the light clears, and check the file name and format.
  3. BIOS updates may affect a PC in various ways. Should any issues with the BIOS arise as a result or your system is unable to boot, please contact your local ASUS support center for further assistance.

The specifications and price are subject to change without prior notice.
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