Hi - because of not enough space on my hd, I have been unable to get updates, until yesterday, when I deleted Microsoft Windows Office for Mac. But I'm going to have to put it back soon. When we had an HP Pavilion Desktop, we had this Maxtor OneTouch 4 attached to it, so it's formatted for Windows. Can I change the formatting and not lose the stuff put on when using Windows? Prob not, right? So, I should get a new external drive? How do you decide whether to get an external drive or increase you hard drive? Thank you for your patience.