Installing 25H2 (on unsupported hardware) has partially bricked laptop.

I clean installed 25H2 using Rufus on my old Dell Vostro 3750 laptop. It seemed to be going well until what was the final restart of the install when it froze on the Dell splash screen forcing me to use the power button to regain control. After that it booted into Windows and Winver showed 26200.9457

At this point I discovered a major problem. The Vostro has four USB ports, a USB2, two USB3 and one of those USB/other ports. The USB3 ports seemed dead although they do supply power to a drive. Nothing recognised. The other two work normally. Nothing obvious broken in device manager, however it seems much deeper than that...

It gets worse, those two ports are not now recognised in the BIOS. A reboot with a bootable flash drive in place simply produces a flashing cursor, no splash screen.

I took the laptop battery out and left it all overnight. First boot up actually failed as soon as it went from splash screen to Windows with the display freezing at a low contrast level. Again power button used to regain control. This time it booted to Windows and a drive was recognised audibly when plugged into the USB3 port (I got the Windows chimes a drive had been connected) but then nothing. All as before.

I can only guess that the USB 3 controller has been latched into some indeterminate state by that first install freeze.

I am contemplating removing the CMOS battery but its a major strip down to pretty much the last nut and bolt to reach it. Or as its an old machine just used for trying stuff on I could leave it as is.

The BIOS can be accessed on boot and all looks OK. I have repeatedly tried loading the defaults in the BIOS but nothing works.

So it seems Windows or I guess even an update that goes wrong really can brick hardware.

Sorry to hear your troubles installing Windows 11 25H2. By the way, where did you download Windows 11 from ? Microsoft website or through Rufus app or someplace else ?

Was your laptop connected to internet during Windows installation ?

The ISO was direct from Microsoft.

The laptop only connected to the internet during the final part of the instal when I entered my MS account details. The install really was clean and the HDD (well SSD) taken down to unallocated space using the installation media.