When connecting to a Windows 2008 Server using remote desktop from a Windows XP client running service pack 2 or earlier, you get the following error message:
The remote computer requires Network Level Authentication, which your computer does not support.
To enable NLA in XP machines; first install XP SP3, then edit the registry settings on the XP client machine to allow NLA.
Configure Network Level Authentication
- Click Start, click Run, type regedit, and then press ENTER.
- In the navigation pane, locate and then click the following registry subkey: HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlLsa
- In the details pane, right-click Security Packages, and then click Modify.
- In the Value data box, type tspkg. Leave any data that is specific to other SSPs, and then click OK.
- In the navigation pane, locate and then click the following registry subkey: HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSecurityProviders
- In the details pane, right-click SecurityProviders, and then click Modify.
- In the Value data box, type credssp.dll. Leave any data that is specific to other SSPs, and then click OK.
- Exit Registry Editor.
- Restart the computer.
Credits
This solution is originated from Sound Enterprises here.