****First step - make sure XP Service Pack 3 is installed.****
1. Hold down Windows Key and press the letter R at the same time - the "Run" command will be shown - type in Regedit and hit enter.
2. In regedit - browse to the following key:
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 Regedit.
9. Restart PC
Enable Server to allow connections from XP Machines: Server 2012 R2
1. Hold down Windows key and press the letter X
2. Select "System"
3. Go to "Remote settings"
4. Remove tick on the option "Only Allow connections from computers running remote desktop with Network Level Authentication"