1. I have an old PC running 32 bit windows 7 with 200gb of data I want to extract. 2. Most of this is music,pdfs, power points, and regular res. video. Only a few individual files are above 4gb. 3. I want to backup this data onto a portable hard-drive and plan on transferring it onto a MacBook with 256gb flash storage(when I buy one). At my local target the Seagate Slim 1TB is on sale for 70. The WD Ultra 1tb costs 80. Is WD's encryption feature(the reviewers say it offers this while seagate doesn't) relevant only if I intend to use Windows exclusively?