Hey, I have a similar issue. I'm trying to service a computer that is running 7 32-bit Home Premium that when I attempt to boot into the OS on the hard disk, it only gives me a black screen and a cursor. No login screen, or anything else. So I figured "I'll just boot into safe mode and fix it". Same problem. I tried using the repair utility, same problem.
I started to think this was the result of corrupted System files, so I tried to boot from an optical disk to try and repair the OS. Here is where it gets weird: the same problem (black screen and only a cursor) occurred when booting from an optical disk! I now think that it's a hardware problem, as I know that this CD works.
Anyone have any ideas?