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Does anyone have any advice on the best Linux flavor to run on a Dell Optiplex GX260 tower? I have Unbuntu now, but it is very slow. All the forums I have visited have advice but from like 2006! Also, it has only 1 GB of RAM. I am usually a Windows guy so any help would be appreciated. Thanks!

PS - Stupid question - Would dual booting with Windows 7 slow it down?