How to get to know how to change the drive letter in Windows 2000 guide:
Click Start, Help, in the Windows 2000 Help select Index tab, in the "Type in the keyword to find:" box type in the "drive letters", find "changing", double click on it, read the manual, and if you still want to reformat, you have the full power to do that 😉
And why would you want to change the system volume drive letter? (just curious)
..this is very useful and helpful place for information...