Accessing Blocked Files in Vista

Let's say a friend sends you an executable file (and you run antivirus on it and find that it is safe). But you try to run the file and you receive the following error message:

Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.

Try the following:

Right-click on the file and choose properties. At the bottom of the General tab, look for a section for Security that says "This file came from another computer and might be blocked to help protect this computer." Click the Unblock button.

You should be able to run the file now.