For this, you have to click Start again on the Search tab so that Portable Update can determine which updates are missing on the second machine. If you copy the tool’s entire folder structure to a USB stick, you can easily install those updates on a second computer. List of available patches in Portable Update
If you click Start again, Portable Update downloads the selected patches as CAB files and stores them in its Cache folder.
Portable Update will search for the available updates for this particular machine and display them on the Download tab, where you can then select some or all of the updates. First, you have to select the tool’s Search tab and then click Start. Portable Update makes use of the fact that Windows Update stores all updates in the folder mentioned above.