Vista – Windows installer service could not be accessed
Posted by chelfers | Posted in Computers, Windows Fixes | Posted on 06-12-2009
Tags: regserver, vista 64, windows installer, wow64
2
*facepalm*
What a mini nightmare this turned out to be, but after an hour of unsuccessful googled fixes we have a winner! Here is a brief list of what I tried and then the one that worked and made the most sense; sorry I don't have post-backs to where the information came from, and I do not take credit for any of these fixes.
Attempt 1
- Boot into safemode ( f8 when restarting the computer )
- Click Start, then click run ( or hit windows key + r ), then type cmd and click ok
- Type in the following:
- %windir%/system32/msiexec.exe /unregister
- %windir%/syswow64/msiexec.exe /unregister
- %windir%/system32/msiexec /regserver
- %windir%/system32/msiexec /regserver
- Reboot and try your install again
Attempt 2 - Little more advanced, please don't screw up your system
- Click Start, then click run ( or hit windows key + r ), then type regedit and click ok
- Navigate to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer\Enum]
- The view pane should look like this:
"0"="Root\\LEGACY_MSISERVER\\0000"
"Count"=dword:00000001
"NextInstance"=dword:00000001- If it looks similar right click Enum entry in the left pane tree and select delete
- Reboot and try your install again
Attempt 3 - Little bit more advanced, be careful!
- Click Start, then click run ( or hit windows key + r ), then type regedit and click ok
- Navigate to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer]
- Look for the key name DisplayName and make sure that the value is set as C:\WINDOWS\SysWOW64\msiexec.exe /V
- If you change it reboot
Attempt 4 - this worked for me
- Click Start, then click run ( or hit windows key + r ), then type regedit and click ok
- Navigate to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer]
- Look for the key name WOW64, double click it and change the "Value data" to 0
- Reboot
In attempt 4, the WOW64 key value of 1 tells the installer to only deal with 32-bit installers and error on the rest, by changing this to 0 the system is now open to install 64-bit apps ( hopefully ) with less headaches.
Hope this helps someone!

