Go to Control Panel -> Add or Remove Programs -> Microsoft .NET Framework 2.0
Click the Change/Remove button and click Repair.
If it doesn't allow you to repair uninstall it with
http://download.microsoft.com/downlo...bd/msicuu2.exe, if it does repair for you, skip this part.
After you have repaired/reinstalled .NET Framework 2, restart and your Tablet PC Input Service will work correctly.