Cannot install or uninstall programs

[Rick]

Cannot install or uninstall programs

SYMPTOMS
The following (or similar) error resulting in an inability to install or uninstall any program:
\"Error 1719\" The Windows Installer service could not be accessed.\"

CAUSE
Nonexistent, incorrectly installed, unregistered, or corrupted \"Microsoft Windows Installer Service\" (MSI).

RESOLUTION
The following fix is a simplified version of the steps listed on Microsoft's Knowledge Base: http://support.microsoft.com/kb/315346

Step 1 – Check to see if MSI components are present and registered correctly…
• Confirm the presence of the installer service
o Click Start, and then click on Search.
o Click All files and folders.
o In the File name box, type msiexec.exe, and then click Search. The location of the file should be %WINDIR%\\System32 where %WINDIR% is your Windows directory.
• Confirm the registry entry for the installer service
o Click Start, and then click Run.
o In the Open box, type regedit, and then click OK.
o Navigate to HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Services\\MSIServer.
o Make sure the entry for ImagePath is \"C:\\WINDOWS\\system32\\msiexec.exe /V\". If it does not reflect this location for msiexec, make sure that it does by creating and\\or editing the registry key using a \"String Value\".
• Register msiexec.exe
o Press F8 to enter Safe Mode.
o Once in Safe Mode, click Start, and then click Run.
o Type the following line, and then click OK: msiexec /regserver
o Shutdown and restart your PC.


Step 2 – Re-install the service…
• Re-install the Windows Installer by first disabling the backup in DLLCACHE (not System32)
o Click Start, and then click Run.
o In the Open box, type cmd, and then click OK.
o At the command prompt type: attrib -r -s -h \"%Windir%\\system32\\dllcache\" this remove the Read Only, System and Hidden flags.
o At the command prompt, change directory by typing: cd %WINDIR%\\system32\\dllcache
o Now type the following lines, pressing ENTER after each line...
ren msi.dll msi.old
ren msiexec.exe msiexec.old
ren msihnd.dll msihnd.old
...This renames and thus disables the Installer Service backup files.
o Shutdown and restart your PC.
o Update the Windows Installer files to the latest release using Windows Update.