Windows Installer error when upgrading from vCenter 4.x to 5.0

When upgrading a vCenter server from version 4.x to 5.0, you may encounter an error:

“The Windows installer service could not be accessed. This can occur if you are running windows in safe mode, or if windows installer is not correctly installed. Contact your support personnel for assistance.”

You may genuinely have a broken Windows Installer service but first thing’s first: Check if the “Windows Installer” service is running. If not, start it and try again. You could also try running “msiexec”. If it’s broken, it won’t run at all but if the dialog box comes up, then maybe the problem is somewhere else. In my case, I found the culprit to be in the registry. Checking the “WOW64” key under “HKEY_LOCAL_MACHINESYSTEM\CurrentControlSetServices\msiserver”, revealed its value to be set to 1. This means that Windows Installer can only be used with 32-bit installers. For 64-bit installers (which the vCenter installer is), the key has to be set to 0.

It is possible for a x64 server to have the registry key set like that, if in its lifetime, it has seen both 32 and 64 bit installers running. Needless to say, I changed the value to 0 and restarted the server (a restart of Windows Installer service would have sufficed but I just wanted to be sure). Re-running the installer after the server came back up, worked perfectly.

About the Author: Ather Beg

Ather is a Senior Specialist Solutions Architect and works for Amazon Web Services. His focus is on all things related to cloud, technology, storage, virtualization and whatever comes in between. Being in the industry for over 27 years, Ather has been a vExpert for 10 years running and is also vExpert NSX/HCX/CloudProvider. He has also been an official VMware blogger at VMworld EU and US and is one of the founding members and contributor to Open HomeLab Wiki and co-hosts @OpenTechCast as well. Ather’s natural habitat is tech events like VMworld, Cloud (and other) Field Days, VMUGs etc. and he thrives on meeting like-minded people and having a good old chat about technology. He’s friendly and not dangerous at all so please do interact with him whenever you spot him in such surroundings.

2 Comments

Victor April 6, 2012 at 9:33 PM - Reply

Thanks for the info, please can u mail me the link where i could upgrade my window installer.
- Ather Beg April 12, 2012 at 8:26 AM - Reply
  
  Hi Victor,
  
  The article wasn’t really about Windows Installer but a quick google reveals the following link for the most up-to-date Windows Installer site (at the time of writing: http://www.microsoft.com/download/en/details.aspx?id=8483&WT.mc_id=MSCOM_EN_US_DLC_DETAILS_121LSUS007852 Please do ensure that you select the one appropriate for your OS.
  
  Ather