About the Error
If you are upgrading from Small Business Server 4.0 to Small Business Server 4.5, the upgrade process may hang in the middle of the installation of SBS Administrator. The error message will be displayed. If you have also attempted to register the Srvcstat.ocx manually by running Regsvr32.exe, the upgrade will still be unsuccessful, and you will get the same error message.
Tips for resolving the error code 0x80040201 in Windows.
This error occurs if the Comcat.dll you have currently installed is not the right version. When you attempt to register the Srvcstat.ocx file, the Comcat.dll will be called, and if Comcat.dll is not version 4.71, the registration will not take place.
To fix the problem, replace Comcat.dll version 4.71, with the file that is included in Microsoft Windows NT 4.0 Service Pack 4. Do this by going to the Winnt.sbs\System32 folder. First, find the existing Comcat.dll file, and then rename it to: Comcat.old, so it will not be called. Then, expand SP4 to a temporary folder by executing this command: c:\program files\microsoft backoffice\sp4setup /x. Then, check the temporary folder for the new Comcat.dll file. Copy this new file manually, from that temporary folder to the Winnt.sbs\System32 folder. After you have copied it, then register the new Comcat.dll file by using the regsvr32.exe utility. You can do this by typing in this command: regsvr32 c:\winnt.sbs\system32\comcat.dll. Then, restart the BackOffice Setup, and complete your upgrade.
TipFor more information, please see: How to fix Update error #0x80040201