SQL Server uses the following registry keys:
All Versions
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSSQLServer
 - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer
 
Version >= 6.0
- HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSDTC
 - HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SQLExecutive
 
Version >= 7.0
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SQLServerAgent
 - HKEY_LOCAL_MACHINE\Software\Microsoft\Microsoft SQL Server 7
 - HKEY_LOCAL_MACHINE\Software\Microsoft\MSSQLServ65
 






