yeah you do need them, but I suspect windows installed them during the install process, or subsequently as it has been probing MS's site for updates.
In Device Manager,
To get to it you can simply press the windows key on the keyboard + R, and enter "devmgmt.msc"
If there are no issues found, then there would be no "colored marks", nor would there be any "sub-items" opened beyond the main headings (great!): So the drivers you didn't see might have been under the header "Sound, Video and Game Controllers" (NVIDIA and Conex't
you said the sound is working? right.
other than the video - and the drive - all is okay seemingly?