invalid system disk win2k

[pipelogger]

I have been trying for a week to fix this problem. Wanted to fix on my own but I give up.
HP desktop 6553,WIN2K. Any time you boot,invalid system disk. I have disconnected everything, ran maxtor diag, hard drive shows good. Put hard drive in external case on another computer and all shows up. Swapped memory, cables, cd player, floppy, you name it. Tried bootdisk, just stalls.
You might say just reinstall os. The bios shows the cd drive as atapi cd but in the boot sequence you can not put a plus next it. If you put a cd in nothing works.
If I swap another hard drive it states error reading disk.
What in the world am I missing?
Only thing left is mb or ps, right?

[Panama Red]

Possibly a defective cd drive is causing an ide error. Try a different drive and see what happens.

[pipelogger]

Swapped memory, cables, cd player, floppy, you name it. Tried bootdisk, just stalls.

[EzyStvy]

Did you make ANY type of change to the pc prior to this issue starting?

I would get all important files off the drive while you can...and then try:

Description of the Windows 2000 Recovery Console
http://support.microsoft.com/kb/229716

Consider the following sections:
FIXBOOT
FIXMBR

[pipelogger]

Update, tried different hard drive and boots right up. So I know where the problem lies.I will try what EzyStvy says and get back. Thanks