I may be wrong, but I dont think you could have done anything to the original bios with only a softmod, so you shouldn't have to worry about that. You could have messed up your dash files on your hard drive though. If you have your chip installed and working, try downloading a copy of Slayer's or AutoInstaller Deluxe (AID for short) and burn it to a cd or dvd. From those disc's, you can then restore the MS dash to a working state, and you will also be able to install some alternative dashes included on the disc. I would start by booting to one of those disc's and format your C drive (your E drive will have any existing game saves on it) and let the disc reinstall the MS dash so you know there wont be any stray files to mess it up.