C# Newbie - Having a problem

Question

I have a test file located here: C:\test.txt I am trying to see if the file exists: bool exists; exists = System.IO.File.Exists(@"c:\test.txt"); exists always returns false even though the file does exist the same thing happens if I try using: System.IO.File.Delete(@"c:\test.txt"); even thought he file exists, it is never deleted. Am I missing something? What is the purpose of the @ symbol before the file name? Thanks