SmartFileSystem (SFS) will not work on an unexpanded A600 as it requires a 68020 processor or better. You need to install using basic FFS. If you format the harddrive using either FAT or NTFS then you're Amiga will not recognise it. If you want to use the HDD on your PC under WinUAE then you can use FFS but you have to run WinUAE to be able to read the HDD.