acces denied in windows vista using C# System.IO

[bik]

Hi guys, it'll be great if some can help me, I have a problem geting directories Url in vista scaning the C:\\ disc, it says that the acces is denied, i had disabled the UAC, and have administrator privilege but the problem persist, I'm using this line to scan and when i try to scan documents and settings, program files or some directory i get this error: Eseption do not controled in the aplication. Access denied to C:\\Documents and settings

string[] carpetasScan = System.IO.Directory.GetDirectories(url);

Some one know how to get acces to scand and copy files?