I see what you mean, but isnt the purpose of DA to help get around the problem of differing architectures etc? I havent had many problems with DA until now.
The image i was trying to use was from the same model Dell (t3600), but it had a raid controller card. For unknown reasons Dell seem to have started to ship the t3600s without that card now, so thats why i had to DA it.
After reading your theory this morning, i tried a different image that was built on a different model dell that didnt have a raid card, because it might have been a closer match architecturely, but still no luck.
Last time i looked at sysprep it was a mess, so i'd rather not go that route but i will read up on it again.
For now i am installing windows from scratch! :-(
Thankyou for your suggestions