Well, I've got the unpacked files on a DVD and the 'new' thing can't see the disc at all. It can see files on some discs, and indeed installed XP onto logical D. But it will not see the +r disc.
There's a BIOS mystery. It want's to find a floppy, but shows no DVD...unless it's offering to start from it!
This firmware seem an awful mixture of pre-history and modern items. Most odd. Given the board is SATA it should agree with the invoice of about 2008 - not too aged.
"Secondary master drive ATAPI incompatible." Thing is, I don't know how to set the BIOS if it's not listed. It seems to object to it being a second SATA drive.
I'm putting my money on a duff or wrong setting DVD right now. I don't think it's gone into slow mode with it unplugged. In fact, when it did bog down, and I pulled the Serial lead, it freed the system up. so, hopeful about this.
I'm going to resort to alcohol and a little of this.