Unable to run laptop.

I’ve got a laptop that had Windows 2000 on it. I hooked up a USB external hard drive that had Windows 98 on it to delete some things from it. Now when I start my laptop it asks which operating system, default being Windows 2000. So i click that and it says that a file is missing. Alright, there’s nothing on it anyways and I was going to install XP anyways. So I boot from CD with the Windows XP disc in it and it asks which operating system to chose from, I click 2000 and same error. (Clicking the other one just freezes it, as 98 has never been installed nor anyother OS). I don’t care whatver is on the laptop is lost just as long as I can get this thing running again. Thanks for any help!