Today I met a client having such a problem when installing software: “Windows Installer service could not be accessed” and I searched through Internet, found the solution as below:
If your system is Win XP, when installing Office2003, if error occurs that could not access Windows Installer service, then probably you run Windows in safe mode or Windows Installer is not installed correctly (actually all MSI format of applications using Windows Installer service could not be installed normally); check “Windows Installer” service status in “Service”, generally, it’s disabled; when you try enabling the service, you will find the service is already disabled, or Windows Installer service is already marked as deleted; when you try reinstalling Windows Installer service, system would prompt “The specific service is already existed”—this is what you want.
Solution (approved on WinXP/Win2000):
First code the content below in notepad, and save as installer.reg file, double click it to import to registry;
Run “CMD” command prompt, enter “msiexec /regserver” and press Enter;
No need to restart, then it’s done already!
Windows Registry Editor Version 5.00