Let me see if I understand. You installed Windows on a hd on one computer and then took that hd and put it in another computer? And you expected it to work? Is that correct?
First, you are violating the EULA - one OS CD, one computer.
Second, unless the two computers are EXACTLY identical, you cannot do what you want to do anyway. As you are finding out, the OS will not load on the second system. You need to install the OS on the HD while it is in the system you want to use.