Fixing Windows Installer Erroc Code 1601

Fix: Error Code 1601 Windows Installer - Windows 7 or Vista
Click Windows Start button, in the Start Search box, type the following command and then press enter:
%windir%\system32\msiexec /unregserver


Nothing will be prompted to you because the registry method takes less than one second to be completed.


Next, return to the Windows Start button, in the Start Search box, type the following command and then press enter:
%windir%\system32\msiexec /regserver


Now that the msiexec has been re-registered, you may try to run any Windows Installer to check if the issue is solved.


Fix: Error Code 1601 Windows Installer - Windows XP or 2000
Click Start -> Run -> type CMD in the run box, and then click OK.
A MS DOS window will be prompted to you. Type the following command and then press enter:
msiexec /unregister


Do not close your MS DOS window after this step.


In the same MS DOS window after performing step two, type the following command and then press enter:
msiexec /regserver


Now that the msiexec has been re-registered, you may try to run any Windows Installer to check if the issue is solved.