On your Windows 2000 or greater servers, XP Professional, or Vista Business computers you have the ability to control the file permissions on that computer. To change these file permissions so that people logging in on your server (or peer to peer network computer being used as the data server) can use them you simply go to Start->Programs->Accessories->Windows Explorer. Depending on your version of Windows this may vary slightly.
The next step you should take in changing your file permission is you should locate the file in the Windows Explorer that you want to change. You then right click on that file and choose Properties.
When choosing the Properties command it will bring up a Properties Window for that file. Choose the security tab and make sure that "Everyone" has the Full Control box checked. If "Everyone" is not shown, you should click "Add…" then "Everyone" and click Ok. This will give everyone that logs onto the server full permission to that file.