Edward, welcome to FF!
In my experience, air bag codes can not be read with a standard OBD II scanner. And, yes, both the seat belts (buckles and pre-tensioners) and the airbags are part of the SRS (Supplemental Restraint System which has its own control module, located beneath the center console. When the airbag light is on, the entire SRS is disabled, therefore, no airbags, no pre-tensioners, or anything else which is part of the SRS.
I think it unlikely that the window regulators are connected to the SRS, except, as you surmise, by a wiring short. Good Luck.