answer:As far as I recollect, Windows XP can natively support anything up to 500GB or so, with larger drives to be partitioned in sections (making it drive C:\, D:\, E:\ and so on until full capacity is used). That said, I have a 500GB external hanging off my machine right now. The only issue I ever had with it is that it originall came formatted as FAT32, and not NTFS. Since I use the drive for gameplay as well as capturing/editing HD video, anything over a particular filesize was being rejected by the drive, which is what prompted closer inspection. Open up your command prompt (Start, Run, ‘cmd’) and try throwing one of these at it: convert drive letter: /fs:ntfs So for example, if you plug in the external drive and it happens to register as drive D:\, convert d: /fs:ntfs If there’s data on it right now, doing this WILL NOT destroy that data, so it’s perfectly safe to do without having to reformat/copy all your files away from it. Let us know.