Quote Originally Posted by OmegaOne
...when i put things back the way they were and restarted i got this error:

NTLDR is missing
Press Ctrl+Alt+Delete to restart
I think that you didn't quite put it back the way it was -- there's no way that the Knoppix CD would clobber your MBR unless you told it to. What's likely is that you set it to boot from something other than IDE 0 or the boot order has Windows confused -- I've seen this happen myself. The Dell tip is applicable, as well.

The "last resort" is not a reformat of your hard drive, but a reset of your BIOS settings, possibly corrupted. Copy the settings down for refrence then dump the CMOS according to your motherboard's instructions, then re-enter the settings in the BIOS setup screens as needed.