You need to start over - sort of. If you can get access to the HD from your PC you can reverse the damage quickly and easily. Either use xboxhdm and your eeprom to unlock the disk, then run xbrowser, OR hotswap and use either xboxhdm/xbrowser or xplorer360 beta 6. Once you have access to the disk you rename the following files, in this order:
C:\xodash\Xbox.xtfN to C:\xodash\Xbox.xtf
C:\xboxdash.xbe to C:\xb0xdash.xbe
C:\xboxdash.xbeN to C:\xboxdash.xbe
C:\xodash\xonlinedash.xbe to C:\xodash\x0nlinedash.xbe
C:\xodash\xonlinedash.xbeN to C:\xodash\xonlinedash.xbe