the xp folder

I intalled vita but i moved xp in a folder named windows.old so if i didn't like vista i could boot xp.i liked vista so how can i delete the xp folder from my computer(it's 70 GB so..)?? I tried to delete it from vista's explorer but it couldn't delete it because it was a windows folder. How can I delete it?? Please help(my computer is 110 gb so i don't have enaugh space...)
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I intalled vita but i moved xp in a folder named windows.old so if i didn't like vista i could boot xp.i liked vista so how can i delete the xp folder from my computer(it's 70 GB so..)?? I tried to delete it from vista's explorer but it couldn't delete it because it was a windows folder. How can I delete it?? Please help(my computer is 110 gb so i don't have enaugh space...)