Yep, he could do that no worries. What he will lose, though, is
settings. So for example if he has set up his PC for connection tio a certain LAN, or set up modem settings, etc, he has to write them all down before he formats the old drive.
That's the beauty of the wizard - it lets you choose what settings to save, and what not to worry about.
A newly installed NTFS system will happily read local files from FAT32 - but it won't work in reverse (not easily, anyway).
Cheers
Mick