Boot to the normal Windows desktop with boot logging enabled. Save the boot log just created to a different name or location so it will not be overwritten on the next boot.

Reboot the system in Safe Mode, which also creates a boot log. Compare the two logs, identifying differences in drivers loaded during the two boots. You can print both files and lay them side by side for comparison. An easier method is to compare the files using the Compare tool in Microsoft Word.

Use the System Information utility or other methods to identify the hardware devices loaded during normal start-up but not loaded in Safe Mode. Which devices on your system did not load in Safe Mode?

As you identify the drivers not loaded during Safe Mode, these registry keys might help with your research:

Lists drivers and services loaded during Safe Mode: HKLM\System\CurrentControlSet\Control\SafeBoot\ Minimal

Lists drivers and services loaded during Safe Mode with Networking: HKLM\System\CurrentControlSet\ Control\SafeBoot\Network