Let's say you just completed all of RE5, and you happen to want to play it all over again from a fresh start. TOO BAD! Capcom made it so you cannot delete or reset save progress in the game, and you can't delete the save file or else Steam Cloud will just bring it back. Disabling Steam Cloud does work, but it will not save any progress you make, ideal for speedrunners, not so much for casual players.
Here is the most straightforward and effective solution to this problem.

Go to
C:\Program Files (x86)\Steam\userdata\<user-id>\21690\remote
and you will find savedata.bin
Open the savedata.bin file with Notepad, and remove a few lines.
Reopen the game, and it will tell you that the save file has been corrupted and cannot be loaded.
Continue anyway, it will tell you that if a save cannot be loaded, the game cannot be saved, click Retry.
A new, fresh save will be created!