Im planning to reformat my whole computer so Im backing up my whole Itunes library. I went to Itunes-file-library-back up to disc. Now, I dont have a disc but I have a portable external hard drive. How do I go about it? is there other option besides backing it up to disc? Btw, I already back up my whole pc. Will that be enough or I have to separately back up the itunes. Thanks in advance!