When upgrading from Windows 7 RTM to SP1 on a clean Windows 7 RTM build, binaries such as usbport.sys, usbehci.sys and winusb.sys may not get updated. Machines that have INF files from OEMs to install USB drivers with a custom description will not get affected. This issue doesn’t exist if you use a slipstream version of SP1.  A new update will be released very soon to address this issue.

This issue manifests if two INF files refer to the same binary. So far we aware of only USB drivers being affected by the SP1 upgrade process because of the way USB INF files are structured. In the USB case, usbport.inf and usb.inf both refer to usbhub.sys. Depending on which INF gets serviced first the other INF gets ignored, and that leads to a mix of RTM and SP1 binaries. As far as we know, this hasn’t lead of any system crash because the fixes to these binaries don’t have any cross binary dependency.