Windows Installer Error

I am running Windows 2000 and am getting the following error when attempting to install new programs "The Windows Installer Service could not be accessed. This can occur if you are running Windows in safe mode or if the Windows Installer is not correctly installed." I have downloaded and reinstalled Windows Installer 2.0 and that did not solve the problem. Under the Windows Installer service properties, I noticed that path is C:\winnt\installer\msiexec.exe /V. Other Windows 2000 systems point to C:\WINDOWS\System32\msiexec.exe /V. Any assistance will be greatly appreciated.