Vista - Windows Installer Services could not be accessed

I have been trying to Install the Adobe products, and have been getting an error stating: "Windows Installer services could not be accessed. This can occur if Windows Installer is not correctly installed. Contact your support personnel for assistance."

I have tried the following options to fix the above problem:

A
11. Go to a Windows Vista (Any Version) computer that has the Windows
Installer service running correctly and run regedit(Start-Run-Regedit)
2. Go to the location
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\msiserver
3. Right click on this key and select "Export" and save the key to a Flash
Drive or other.
4. Run sfc /scannow on the damaged Vista computer - you won't need the
install disk as it goes to backup files on your HD. Do not reboot when
complete
5. Double click saved .reg file from working machine and import registry
settings into damaged Vista computer.
6. Now reboot and try to install/uninstall

When I did the sfc / scannow: it said that there were some problems that were not fixed, and they were logged to C:\Windows\Logs\CBS\cbs.txt. When I went here there were many errors that were logged and I could not understand what these are...

B
I tried to reinstall Windows Installer:
In the process of renaming the msi.exe file, in the command prompt, logged in as an administrator:
c:\windows\system32> ren msi.dll msi.old

I get the message: Access is denied

I have also turned off the UAC.

C
I have also checked that the Windows Installer is ticked and running in the System Configuration Utility

D
I have also updated the Image Path of the MSIServer in the Registry with:
C:\Windows\System32\msiexec /V

I am totally stranded with options. What else can i do to get windows installer working.

Installing a fresh copy of Vista will be my last option.