HELP NEEDED!

I've been trying to configure my home PC so that I can create a website for a university module using Dreamweaver MX, all was going well until I had to delete some files from my dreamweaver 'sample site'. I have no idea how but my local host seems to have 'got lost'

When I 'run' http://localhost/ it displays 'This page cannot be displayed' & 'HTTP 500 - Internal server error Internet Explorer'

I tried removing the IIS components from the ControlPanel Add/Remove Programs screen, (to reinstall the IIS from disk) but my computer then gets stuck.. it says it is configuring IIS then that it is removing them... Then it stops it doesn't send an error message or anything it just stops on that screen
FOR HOURS!!

Without having to reinstall Windows is there anything I can do?

Regards,
A grateful, novice