I've recently purchased a seagate 1.5TB hard drive and it came with some software on it. i deleted these as i only wanted the hard drive in order to store movies music and pictures. I've already put files on the hard drive with a pc but i can't take them off on my mac or put any more on with my mac. it tells me it is read only. do i need the previous software that i deleted or is there a way to unlock it? if i do need the software is there a way of getting it back?