USB devices won't boot on HP Compaq dc7800 Small Form Factor PC Bios 1.35

[dm_53]

Hello,

I'm trying to run Linux on an HP Compaq dc7800 Small Form Factor PC. When I first got it it was running Bios version 1.32 from 2011 and it did boot correctly all USB devices I gave it, from a Linux install drive to a Windows 10 PE, no problems. I was getting post-install messages that on research led me to update the machine's Bios to 1.35 from 2015.

That's when the trouble started. The machine will no longer boot the very same USB sticks that it would previously same ports and everything. If I do an f9 and select USB device (the second option) it is ignored and the system OS loads, not ideal when I might want to run a Linux pendrive or Windows PE. I go in to Bios and select storage devices and boot order, here the USB device is first, the ATAPI CD/DVD second, and the hard drive third, this contrasts with the f9 menu where CD/DVD is first, USB is second, and hard drive is third.

I've googled and read many forum posts, under storage options there's an option removable devices boot, that is enabled. I thought this would have had something to do with Secure boot and Legacy devices, but reading Hp's site on the issue to disable secure boot those options don't show up in my Bios.

Aside from the removable devices boot option which is enabled as I noted, I don't see any options for secure boot or anything having to do with legacy boot.

Frustratedly I reverted back to 1.32 Bios version from 2011 and the problem is still persisting.

Any help appreciated.
Thanks.
Dave.

[Paul_Tikkanen]

Hi, Dave:

I have a dc7800 CMT running on BIOS v1.35.

I saw your post and hooked it up (I don't use the PC regularly) to see if I could boot from a USB flash drive.

I grabbed a bootable W11 installation flash drive and the PC would not boot from it.

Went right into Windows 11.

But then I forgot that I had set that installer up as UEFI boot and as you found out, the dc7800 does not have a UEFI BIOS, nor does it support secure boot.

So, I had to rummage around, and I found a USB flash drive with W7 on it.

My PC booted up just fine from the W7 installation USB flash drive, so unfortunately, I don't know why your dc7800 isn't booting from your flash drive.

Try a different USB flash drive, and make sure the flash drive is not formatted GPT.

It needs to be FAT32 or MBR-NTFS.

BIOS v1.35 adds AHCI drive controller support to the boot options settings.

Previous to v1.35 the only drive controller settings were RAID or IDE, with RAID being the better setting for drive performance.

Now that I have this beast running, I may as well let it install the latest W11 security updates and whatnot.