When I attempted to use add/remove programs in Windows XP SP3  to uninstall some recently installed Microsoft programs I got the following error message from the Windows Installer:
"The Windows installer service could not be accessed. This can occur if the Windows installer is not correctly installed. Contact your support personnel for assistance."I am new to this forum and found it as a result of the above problem. I downloaded and tried " Add Remove Pro" and received the same error message. I also used " Add Remove Pro" on my laptop computer which is also running XP SP3 and successfully uninstalled several programs. The installation executable was from the same download on both machines. Suggestions would be greatly appreciated. I am disinclined to re-install XP!
Thank you.
Peter

   I do not know what would cause that.  It obviously is something on your computer.
   I would suggest doing a search on the internet (Google) for the error message.  Put it in quotes, something like this, "The Windows installer service could not be accessed".  Here are a Microsoft page that I found from a Google search - http://support.microsoft.com/kb/315353

Ray,

Thanks, I had found that link also, followed it and eventually found the the key

HKEY_LOCAL_MACHINE, SYSTEM, CurrentControlSet, Services,  MSIServer

was totally missing from the registry. I then imported the key from another XP SP3 machine and rebooted. When running either  Add Remove Pro or the windows capability I received "Setup.exe has encountered a problem and needs to close.  We are sorry for the inconvenience.”...........!!!
I am working on it but any ideas?
Thanks
Peter