Why there are some installed programs missing in "get-wmiobject -class win32_product" output on Windows 7?

If you compare entries from the "get-wmiobject -class win32_product" output with "Uninstall" registry entries, you will many installed programs are missing in "get-wmiobject" output. This is because Win32_Product WMI class represents programs that are installed by Windows Installer.

Windows 7 uses the "WindowsInstaller" registry key to flag if a program is installed by Windows Installer.

For example, if you look at the installed program "Adobe Acrobat Reader DC MUI" in the registry at HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\{AC76BA86-7AD7-FFFF-7B44-AC0F074E4100}, you will see registry key "WindowsInstaller" is set to "1", indicating this program was installed by Windows Installer. So "Adobe Acrobat Reader DC MUI" entry will be in the output of "get-wmiobject -class win32_product".

If you look at the installed program "McAfee LiveSafe" in the registry at HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\MSC, you will see no registry key "WindowsInstaller", indicating this program was installed by the "McAfee LiveSafe" itself. So "McAfee LiveSafe" entry will not be in the output of "get-wmiobject -class win32_product".

⇒ Visible Installed Programs using Windows Installer on Windows 7

⇐ Full Properties of Installed Programs with "Get-WmiObject" on Windows 7

⇑ Uninstall Old or Bad Programs and Software on Windows 7

⇑⇑ Windows 7 Installed Programs