I have a small business and use MS Frontpage as my website software. With all the talk about MS preventing their software to be copied to other computers, I'm relunctant as I may not be abnle to get my MS software operating again.
You need all the original MS Office disks. If you got a machine with MS Office pre installed, you should have gotten the disks as well.
The procedure of reformatting a drive, reinstalling the Windows OS and all your apps, is not for the faint of heart. I learned most of it out of necessity, after a series of semi-catastropes