OK, I followed the helpful guide from life hacker which is linked in other threads and part of the useful dual booting item on PCA click here and I am posting here from W7
A couple of things to look out for. Obviously the boot order need to have the CD/DVD drive listed before your hard drive or in my case my RAID array. I had to change it.
The reboots during install did not all go automatically, I had to select W7 from the two choices on the boot screen (I dual boot with Vista Home) so you may need to pay attention.
Do not do, as I did, which was to press any key on the first reboot which allowed it to boot from the DVD drive, all that did was start the whole install again, not terminal but frustrating and I now have Windows Old file to delete which were installed at my first attempt.