If you are using Windows XP or Vista and the network machine running Windows XP is refusing your attempt for access via network displaying "Access is denied" or "You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions." error as shown below, just follow the simple registry hack to fix it.
- Goto Windows Start Menu -> Run, typin regedit and press Enter key to launch Windows Registry Editor.
- Navigate to - HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Lsa
- Change value of key restrictanonymous to 0.
- Reboot computer to apply change.
You can also use the Registry files below to apply and undo the hack, simply download and double-click to apply.