After my little snafu trying to install knoppix to an external hard drive, I then attempted to boot to Windows. However, I found that GRUB had been written to my internal ahrd drive, and would not let me boot. I get an error 21. I can't seem to find anything on the error, and it seems I'm not alone.

If I boot to Knoppix, is there some way I can change the bootloader back to Windows? Or is it time to reinstall?

EDIT: It seems to be working fine now that I have the hard drive plugged back in. Once the drive is taken out, I have the problems again. What can I do? I am going to try fdisk /mbr from Windows and see if that does anything.

fdisk /mbr in Windows 98 will re-write the mbr for windows. In Xp use 'fixmbr'.

If you install grub on the external drive, then it will only be accessed when it is connected when you boot up.