You need to be in where the file is. If you have format.exe on the floppy you should be in A:. If it is on the cd you should be in D: or whatever letter it gets assigned. Then type in format C:.
If ME is like 98, format is not on the floppy of cd. The startup creates a ramdrive and format is in there. You will have to watch during bootup to catch the drive letter of the ramdrive. Usually after the last hard drive and before the cd.
Hope this helps
Semper Fi