Some Windows 2012-R2 customers see an Error Code 38 when they try to re-enumerate a PnP device which has been previously removed even though a trace of the driver (WDM) for that device indicates its unload routine has been called and it has successfully completed. The description of that error code is:
“Windows cannot load the device driver for this hardware because a previous instance of the device driver is still in memory.”
I don't see how the driver can still be in memory if its unload routine is called. Perhaps the error code 38 indicates another problem despite its description?