I've been asked about this before and some people may not know how to apply save data to certain games so i thought this write up would be necessary.
Firstly you need to know where the game saves to, sometimes you can internet search it online and sometimes you may have to locate it yourself, various places a save file may get placed include the game or emulator location itself, AppData (search the game or emulator name or company names), Documents, Public Documents, Registry (search the game title or company names only in HKEY/Current User/Software, also be careful altering things in the registry as this can cause bigger problems with your PC if you mess something up), these are some of the most common places to search, once you've figured that out you're onto the next step.
Secondly in addition to where it saves to is what the save file is named as and verifying it's the correct source, best way is to start the game or emulator yourself and run it as long as is needed to create a save file, then check the naming of a save you're hoping to put there in place of it and whack it in, start the game or emulator to make sure it all works right, if not then go back to step one.
Thirdly if for some reason you were unsuccessful finding the location of where a game or emulator is saving said data, then it might require more extensive searching like creating a sandboxed environment to help show the linking of where save data may get placed, or moving some folders to see if the save data isn't accessed from certain areas, above all don't stress as there are some games even we couldn't locate where they save to, also if saves don't appear to work even though the location is verified then it's possible it uses some kind of different save format or version or something, sometimes game devs update their games and it alters the saving function, so saves may not port cleanly over either, anyway hope that helps with certain specifics and details.
Secondly in addition to where it saves to is what the save file is named as and verifying it's the correct source, best way is to start the game or emulator yourself and run it as long as is needed to create a save file, then check the naming of a save you're hoping to put there in place of it and whack it in, start the game or emulator to make sure it all works right, if not then go back to step one.
Thirdly if for some reason you were unsuccessful finding the location of where a game or emulator is saving said data, then it might require more extensive searching like creating a sandboxed environment to help show the linking of where save data may get placed, or moving some folders to see if the save data isn't accessed from certain areas, above all don't stress as there are some games even we couldn't locate where they save to, also if saves don't appear to work even though the location is verified then it's possible it uses some kind of different save format or version or something, sometimes game devs update their games and it alters the saving function, so saves may not port cleanly over either, anyway hope that helps with certain specifics and details.