Since a recent Kies update, my Galaxy S2 started to throw the exception "Hardware ID Missing" every time it was plugged into my PC.
The reason is a "bug" in the version of the SAMSUNG USB Driver for Mobile Phones installed with the Kies update. Fortunately, there is a elementary solution.
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This solution consists in installing an older version of the Samsung Driver. E.g.: v18.104.22.168 available here, or 1.4.103 available here. I did use the 1.4.103 with success. No need to uninstall first the version currently installed. You will simply have to confirm during the setup that you want to install that version although another one is already installed.
This issue prevents Kies to connect with the phone via USB. Concretely you see the "connecting" message for a while as well as a spinning icon looping indefinitely.