@rlx009 Fine 
For me the Drive A was listed in âMy Computerâ and dectivating it from Device Manager was enough.
Ingo had pointed me to the right direction Long time to load Rt on Win 10 64bit - #22 by heckflosse but now that link is dead.
Itâs my fault that I didnât reported the solution in time 
@Morgan_Hardwood although the right solution could be correcting GTK behavior by GTK gurus, until then, an item in RT_Wiki and in Rawtherapee.com/Downloads would help âŚ