I just bought a 1TB external drive for my late 2009 iMac that's running Mountain Lion. 1) What file system should I set the external drive as? Should I use OS extended journaled or FAT 32? I want to be able to see the drive's content on a PC just in case. 2) Is it better to use Time Machine to do my back ups? Or should I manually back up my data on a regular basis?