Saves & config
Mass Effect 2 Save File Location
Mass Effect 2 keeps its saved games in %USERPROFILE%\Documents\BioWare\Mass Effect 2\Save on Windows. Copy the whole folder to back a save up; paste it back to restore it.
Save games
1Windows
The original release. The Legendary Edition uses its own folder under Documents\BioWare.
%APPDATA% style variables expand to your own account, and it works
even though AppData is hidden.
Backing a save up properly
Close the game first. A save folder copied while the game is running can catch a file mid-write, and the copy then loads as a corrupt save weeks later when you need it.
If the game uses Steam Cloud, close Steam entirely before restoring an old folder. Steam compares timestamps on launch and offers a choice between the local files and the ones on its servers; restoring while Steam is open often means the cloud copy quietly wins and the folder you just put back is overwritten.
These paths are written by hand rather than imported, and a game update can move them. If one is wrong on your machine, tell us and it will be corrected.
Quick answers
Mass Effect 2 saves
Where are Mass Effect 2 save files stored?
%USERPROFILE%\Documents\BioWare\Mass Effect 2\Save. Paste that path into the address bar of File Explorer and it will open the folder — the environment variables in it expand to your own user folder.