Occasionally, you may find that PDQ Inventory is not listing the same Windows Updates that are appearing as installed when looking on the target computer.
Target Has Not Been Scanned
If a target computer in PDQ Inventory is not showing all of the Windows Updates that are shown in Control Panel > Windows Updates on the target computer, first make sure the computer has been recently successfully scanned with the Hotfixes scanner (included in the pre-built Applications and Standard Scan Profiles).
Types of Updates
PDQ Inventory uses a WMI query to detect which Windows Updates are installed. This query used will list the Windows OS updates installed by Windows Updates or MSU files. It will not show other program updates such as Office, Adobe Reader, etc, that may show in the Control Panel.
When you install a Windows Cumulative Update, it includes all of the hotfixes and changes from all previous updates, so you will only see the single KB number for the installed Cumulative Update. As long as the latest Cumulative Update is installed, the target computer is up-to-date.
Microsoft - WMI QuickFixEngineering Documentation
Microsoft - Windows Cumulative Updates Explained