|Yeah, whatever it is, it's in autoexec.bat and maybe config.sys. You just need to edit it out.|
Depending on your dos version F8 may work. Try tapping it before dos starts loading. If you get a menu choose 'step by step confirmation' and answer No to everything it asks to load. That should leave you at a c:\> prompt and you can run the EDIT command.
If F8 doesn't work you'd need a bootdisk, as already mentioned.
"It was far easier for you as civilized men to behave like barbarians
than it was for them as barbarians to behave like civilized men."