What a safe way to detect installed components of Microsoft Office?

I am looking for the safest way to detect what components of Microsoft Office, if any, are installed on a given workstation.

I've looked at the uninstall key, but it shows components that do not actually exist on the system. I believe this has to do with the way Office can install a component on first access. I'm not fond of looking for executables as the path can theoretically change.

I ended up testing for specific registry keys, taking into account the differences between 32 and 64-bit Windows installs. I'm paying attention to the following registry locations/values:

• HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\12.0\—The base Office12 key on a 64-bit Windows install
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\12.0\—The base Office12 location on a 32-bit Windows install
• Office base path\Outlook\InstallRoot\Path—Key signifying Outlook installation path
• Office base path\Registration\{90120000-0012-0000-0000-0000000FF1CE}—Key for Office 12 Standard GUID
• Office base path\Registration\{90120000-0011-0000-0000-0000000FF1CE}—Key for Office 12 Professional Plus GUID

With these locations I've been able to:

1. Detect whether Office is installed.
2. Detect the version of Office that is installed.
3. Detect whether Outlook is installed.