for those of you who are having issues with the 'BUGCODE_USB_DRIVER' BSOD after installing SP1 from the exe installer (not the dvd iso sp1 installer, or slipstreamed), here is the solution: Binary files in some USB drivers are not updated after you install Windows 7 SP1 or Windows Server 2008 R2 SP1
the article suggests getting the fix from http://update.microsoft.com/
. For offline installers of the fix, check the above mentioned article.
found it here (not needed, just for reference): The Windows 7 SP1 USB Driver Bug (what it is and how to fix it)