Hang on inital boot screen.

[graemev2]

I just downloaded and cut a DVD of debian-10.4.0-amd64-DVD-1.iso. I've cut 2 instances of the DVD (in case it was a writer error)

On the system I'm planning to install, I boot the DVD (multiple time, both discs) an it always hangs at boot, on the 1st screen reading

"Debian GNU/Linux installation menu (BIOS MODE)"

That's it , the numlock button does not even work on that keyboard. Plugged in another keyboard, also nothing worked DoA.

Used DVD in another machine (which I don't plan to install) it came up with same screen, able to navigate using cursor. Plugged another keyboard in, it also worked fine.

Difficult to know where to start . The failing machine runs squeeze, so the previous install mush have booted&worked (I'll try an old squeeze install DVD)

[graemev2]

well, there's a surprise.
Posting here for folks how get a similar issue .
Jessie, Wheezy, Squeeze all have same issue.

Insight came from "sysRescue CD" ...this exhibited same behaviour, but had a counter to "boot unless you make a choice" , it counted down and booted ...next stage was "select a keyboard" (44 for UK)
Here they keyboard worked!

Turns out the solution/workaround was in the BIOS, "Legacy USB support was OFF" changed this to auto. I suspect on would have worked also.

So it looks like the initial boot image on the DVD/CD only supports Legacy USB.

For background the keyboard & mouse are USB and were/are working fine under squeeze ...also worked fine during grub phase. So it's just DVD/CD boot.