For those having problems with windows file access in the default Documents\My Games\TotalMiner path or if you just want to change it to something else, add an entry into the game.ini file like so:
SaveRoot=D:\GameSaves\TotalMiner
or whatever path you want that will not give the access errors.
To access the game.ini file, right click Total Miner in your library, select Properties, Local Files, Browse Local Files.