Win7 will install, but after restart it does nothing

My other hard drive crashed so I decided to plug in my old western digital wd1200. It is a pata btw. I can get it to detect and it is master and all that and after I install windows, when it restarts, it'll loop the installation. Now I tried taking out the disk when the pc reboots, but it gives me the error "cannot find bootable device" or something along those lines. I'm not sure what do do from here and would really appreciate help. I also have a Dell720 if that makes a difference. Thank you

Yea I made sure all of the bios are correct, after the computer restarts, it takes me to a screen that says "there are no bootable devices"

Kaktussoft said:

Install win7 to internal harddisk from DVD. When installation starts wait for first reboot. Don't press any key so you don't let it boot from dvd again. Or simply eject the dvd.

"when it restarts, it'll loop the installation"=> ??? So it boots from harddisk? Or did you press a key so actually booting from dvd again?

What is the exact error message you get?

Ok, after the restart and I've taken the disk out, I get taken to a black screen that says "no bootable devices found" even though I have it in bios correctly and it's detected