There are two things come to my mind reading your post.
1._ The PC can not read the HDD, so boot again from the DVD and reformat the HDD and reinstall again.
2._ The BIOS setup on the PC need to be change. I do not know how old is you PC, so, usually when the PC tries to boot from a HDD, it looks at the IDE 0 if it does not find it, it goes through all the devices in the BIOS order boot list. Not boot device = error message.
Well, hope you still have your motherboard manual (if not, search on the web), there is a setup in the BIOS that will let the PC know that you are using the SATA 1, HDD and not the IDE 0. I do not know which motherboard you have, so you need to find that in the manual.
Well, hope this will help.