Volume resizing in Vista

[Legodude522]

Hello, I have Windows Vista on a 500gb HDD. I'm trying to shrink the Vista partition down to 50gb because I will be tri-booting. I shrunk it down as much as I possibly can in Disk Management but it won't let me shrink it down past 292gb. Why is that? I'd use G-Parted but I know that is flaky with Vista and 7.

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[cboucher]

What kind of problems have you had with G-Parted and Windows 7/Vista? I've used those particular combinations and haven't had a problem.