SQL Server 2000 installation fails with "...previous program installation..."

Error:
        SQL Server 2000 installation fails with "...previous program installation..." error message

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system.

Solution:

• Restart the computer and see if you are able to run the setup. If the restart does not help, use the steps that follow.
• Perform these steps and then run the SQL Server 2000 setup again:
• Click Start, and then click Run.
• In the Open dialog box, type: "Regedit" (without the quotation marks) or "Regedt32" (without the quotation marks)
• Click OK.
• NOTE: Please make sure that you only delete the value mentioned, not the whole session manager key.
• In Registry Editor, expand the following registry subkey:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager 
• On the File menu, click Export.
• NOTE: In Microsoft Windows 2000, click Export Registry File from the Registry menu.
• In the File name text box, type: "Session Manager Key" (without the quotation marks) 
• Click Save.
• In the right-pane of the Registry Editor window, right-click PendingFileRenameOperations. On the shortcut menu that appears, click Delete.
• In the Confirm Value Delete message dialog box that appears, click Yes.
• On the File menu, click Exit.

NOTE: In Windows 2000, click Exit on the Registry menu.

Restart the computer.
Using the Registry Editor, verify that the PendingFileRenameOperations registry value is not available.

Note: The PendingFileRenameOperations registry value may be re-created when you restart the computer. If the registry values are re-created, delete the PendingFileRenameOperations registry value again by completing steps a through j, and then run SQL Server 2000 Setup. Do not restart the computer before you run SQL Server 2000 Setup.

Courtesy : http://potools.blogspot.in