This ASUS M5A78L device fails to start using a USB drive.
This ASUS M5A78L device fails to start using a USB drive.
For a fresh budget build, I’m unable to boot from USB using this older ASUS motherboard. I’ve adjusted the BIOS settings—switched to IDE as default, changed to AHCI, and experimented with RAID. I’ve also tweaked USB3 emulation options (auto default, forced FDD). Each time I attempt to boot, I encounter a floating underscore, which usually indicates the drive isn’t bootable or the motherboard can’t locate it. Despite using this ISO on many other systems, it still fails. I’ve tested various flash drives created with Rufus, confirming they’re bootable. The BIOS version is from 2016, while the latest flash update is 2015—this seems inconsistent. I’m worried about having to reinstall the OS drive on another machine. I’ve tried different USB ports and limited my setup to just one memory stick, though that doesn’t seem necessary. Anyone experienced with this issue has any advice or solutions? Thanks.
Secure boot is enabled. You attempted to configure the BIOS to legacy mode rather than UEFI.
I've tried all the steps before yet couldn't get the USB to boot and install Windows 10... even though I did it on this board for my friend. I got the same board, so I wanted to make things simpler for him. The BIOS doesn't have a core unlocker, which gave me an idea about the device's age. I discovered a workaround by using a different USB flash drive. When I tried it, the flash drive stored data but wouldn't boot. It was puzzling since the Windows 7 USB/DVD tool worked fine. The issue wasn't with the BIOS settings but with the flash drive itself. As with a new device, I checked the HDD list first—USB should be listed first—and ensured boot priority was set correctly (USB first). Make sure the PCI-PNP is enabled and confirm F10 saves "reboots." Hit F8 to choose the USB during boot. If you still face problems, it might just be another faulty flash drive; try preparing the drive again with Windows 7 USB/DVD tool. The Tech Ninja - "P00F"