The problem was reported by one of our readers who was troubled by this Windows Installer service error. The following error occurred whenever we try to install a program and especially with .msi extension.
According to Microsoft, the error occurs if:
• You are using Windows XP in Normal mode.
• The Windows Installer Service that is included with Windows XP is unregistered or damaged.
Any of the following solutions will solve the problem.
• Open the command prompt, type msiexec.exe /unregister, press Enter.
• Now type msiexec /regserver and press Enter.
• Verify that the SYSTEM account has full control access permissions to the HKEY_CLASSES_ROOT hive in the Windows registry. (more info here)
• Ensure that the startup type of Windows Installer service is set to Manual.
• Type services.msc in the Run box and see the Windows Installer service and check its startup type.
• Download a file called msiserver.zip and let it do the work for you.
• Extract the file and double click the .reg file.
• Confirm with Yes and reboot.
The solution here can also help you.
Let me know if the problem is solved.