If it is a simple installation of windows 7, on one HDD and not a dual boot, and not a raid array
then it should not be too difficult to repair
However if you cannot get a boot to the windows7 dvd, then clearly something else is wrong, as the computer booting to the DVD, is not controlled by a defect on the file system of the HDD, as of course, booting to the DVD is how 7 is installed in the first place.
I hope you do not think I am being unhelpful, as of course I have replied to your topic, but I find it a little surprising that YOU - having built the system you say, then have to refer to the Motherboard manual on how to change a boot order
This problem is on my main PC that I build a year ago
, so I found the book for my MB and it told me how to change the boot order
there are basically two ways to change a boot order depending on the system , one is in BIOS change boot priority and is a change effecting all future boots,.
The other is frequently a F key and effects only the boot at that time.
If the one you have tried is the one time boot I suggest you try the BIOS - change boot priority - make the DVD drive the first boot device.
Boot to that with the DVD in.
The Win7 DVD - Please confirm what this is - ie Microsoft Windows 7 - version etc and is the DVD you are attempting to boot from the same DVD as installed the system