Installing updates (or any kind of software) during the logon process is not really the best option. It will "pause" the logon process until the installation is done. We have been using WSUS to keep all clients up to date for years and it is working just fine. A GPO is applied to all affected OU's so the clients get the required settings.

WSUS only works for MS patches and some drivers but it does a great job. I would not recommend driver updates using WSUS instead just update your WDS image regularly.
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Mart

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