Multiregion pc dvd player

I have an IBM Aptiva pc with a Pioneer DVD 115 DVD player. I am in dvd region 4 but have recently purchased some region 1 dvd’s and want to play them on the pc. Is there any free software that will allow me to select the region of the dvd I am watching when I put the disc in? My pc only allows me to select a region a limited number of times and then the pc is set to this region for good. Thanks.