How to Enable Network Level Authentication on Windows XP with SP3

Windows XP with SP3 supports Network Level Authentication within Windows 2008 Active Directory for connecting to devices running it. Network Level Authentication is a more secure method for remote desktop. If your Windows XP with SP3 tried to connect a computer running NLA, you will receive this error:



You will need to configure your Windows XP with SP3 registry to enable NLA,

1. Click Start, click Run, type regedit, and then press ENTER.
2.  In the navigation pane, locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
    
3. In the details pane, right-click Security Packages, and then click Modify.
    
4. In the Value data box, type tspkg. Leave any data that is specific to other SSPs, and then click OK.
    
5. In the navigation pane, locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders
    
6. In the details pane, right-click SecurityProviders, and then click Modify.
    
7. In the Value data box, type credssp.dll. Leave any data that is specific to other SSPs, and then click OK.
    
8. Exit Registry Editor.
    
9. Restart the computer.