I'm helping a friend convert over to a iMac and we bought a external USB hard drive to backup/copy his files from his PC to the new iMac. The external USB hard drive if formatted to NTFS, is there some capability issues when trying to read/write files from this hard drive when it's being used on a Mac? Should I format it for something more compatible? Most of the files are MS Word, Excel documents. Bunch of photos (.jpg's) and there are some Quickbooks for Contractor files but he's going to use Bootcamp & Windows 7 for that.