Determining If a Service Pack Has Been Installed

This article was previously published under Q132475

To determine if your Windows NT 3.x installation was updated with a service pack:

• Type winver at the MS-DOS Command Prompt.
• Choose About Program Manager from the Program Manager Help menu.
• Check the version displayed at System Boot during the Kernel Initialization Phase (when the screen turns blue).
• Start Registry Editor (REGEDT32.EXE). From the HKEY_LOCAL_MACHINE subtree, view the following key:
  

        \SOFTWARE\Microsoft\WindowsNT\CurrentVersion
  
  				

  WARNING: Using Registry Editor incorrectly can cause serious, system- wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.
  
  The value under Windows NT 3.5 and 3.51 is:
  

        CSDVersion:REG_SZ:Service Pack x
   
  				

  The value under Windows NT Advanced Server 3.1 is:
  

        CSDVersion:REG_DWORD:0x300
   
  				

To determine which service pack is installed in Windows NT 4.0, use one of the following methods:

Method 1

During the startup process, Windows NT displays a blue screen with information at the top. This information includes the version of Windows NT being booted, as well as the build number for that version. It also provides the service pack number if any has been installed.

Method 2

From the Windows NT desktop, click Start, and then click Run. Type winver in the Open box and click OK. An About box appears, which lists what build number of Windows NT you are running as well as the service pack version number.

NOTE: This same dialog box can be reached by clicking the Help menu and then click About in Windows Explorer.

To determine version information in Windows 2000:

From the Windows 2000 desktop, click Start, and then click Run. Type winver in the Open box and click OK. An About box appears, which lists what build number of Windows 2000 you are running as well as the service pack version number.

NOTE: This same dialog box can be reached by clicking the Help menu and then click About in Windows Explorer.