Error 1601 means the "Windows Installer" service could be accessed. It could not be running or missing.

Following the steps here -> http://support.microsoft.com/kb/321497/en-us?spid=2529&sid=225

Under the section called "Resolution". It will unregister the service and re-register it.

Then try to install the proofing tools. Let me know if that works or not.

Thanks for your prompt response. I went to that link and it is for WIndows 2000 and NT. I have XP. That web page says " For Windows 95, 98, and ME see Windows Installer 2.0 Redistributable for Windows 9X. Note: Microsoft Windows XP contains Windows Installer 2.0 and therefore can't be installed or upgraded by this redistributable."

Please advise if you have any other ideas. I am stumped.

My bad, I'm being distracted by the Canadiens & Flyers hockey game. Posted the wrong link.

Here v3.1 -> http://www.microsoft.com/downloads/details.aspx?FamilyID=889482FC-5F56-4A38-B838-DE776FD4138C&displaylang=en

I tried msiexec /unregister and then msiexec /regserver. The system did nothing, changed nothing. MY Windows Installer appears to be corrupt. Can you tell me how to fix this? I am unable to install or uninstall a program. I even ran "SFC /scannow" and it churned away but left me with no messages and no change to the system. Please advise.

Try installing Windows Installer 2.0

Its available here -> http://www.microsoft.com/downloads/details.aspx?familyid=4B6140F9-2D36-4977-8FA1-6F8A0F5DCA8F&displaylang=en