Well nobody seemed to want to help me but a friend has sorted it for me so I'll tell you all the problem in case it happens to you!
Before i installed windows 7 I put a new dvd writer in, with a sata connection.
On my motherboard there are 4 sata sockets, 2 blue and 2 black coloured.
The hard drive is plugged into a blue one and I had put the dvd into a blue one too.
My friend moved the dvd to a black socket and this has cured the problem! there must have been a conflict between them.
Now it boots up in about 40 seconds,Great!!