XPS One 2710 DVD/CD device driver missing - fresh Win7 install

I'm trying to install Win7 on a new hard drive in a XPS One 2710. The old hard drive died.

After choosing 'install Windows', I'm getting the old 'DVD/CD device driver missing' issue. But nothing I try works. 

I have:

- tried to install from 2 different DVDs, and a USB stick.

- downloaded AHCI drivers, etc, and browsed to them on a stick, but it says 'no new device found'.

- tried booting from a USB drive containing Windows. BSOD after the 'starting Windows' bit.

- tried repairing Windows on a USB drive. Says repaired, and restart. BSOD.

- tried installing another HDD with a working Win7 (from a different Dell machine). When booting, BSOD after 'starting Windows' bit.

Anyone got any ideas? Thanks.

SOLVED - it just started working........