Only thing I can tell you is it is a VXD or Virtual Device Driver hanging the system up. Go to C:\Windows file and find the Bootlog.txt file in each OS, open it up, read thru or print it (warning, this will be a long print process, have plenty of ink, paper & patience on hand if you do) & look for a failed VXD device (device that tries to load & fails during the boot up sequence in both OS's as they attempt to load). Once you determine the device, try reloading the drivers for the device or uninstalling the software that loads (or calls for the loading) of the VXD (virtual device).
One more thing, is it possible you use the free Zone Alarm firewall and upgraded while the firewall was open & running? Sometimes that causes the symptom youcall out of a failed VXD hanging up the system, if so, there's an easy fix of just deleting the VXD file, uninstalling the software for the firewall, downloading & installing it anew.
Good Luck!