I bought a seagate External hard drive when I was still a PC guy. Now when I try to write to it from my mac it gives me an error and wont let me write to it. I can read from it and all, just cant write to it. I'd like to use it as a scratch disk for video editing. Any ideas on what to do? I think I need to reformat it but have no clue how to do this.......I should have kept that darn install disc it came with.