I recently saw a post regarding the USB to 232 driver not working on Win 11.
I have just done an upgrade & going through all my software & checking it's compatibility, so far so good only problem was the Prolific 2303 AT chip driver, I upgraded the driver recommended by prolific but still no joy, eventually found (I think on the prolific website) a driver called PL2303G_DCHU_DFx_Win_21H2_v5.2.0.2_20210720_ML_Driver
Although did not specifically sy it was for Win11 this one worked.
The one recommended for win 11 on their website did not support the AT chip.
Hope this helps.
here is the link I used, scroll down & select win 11 installer
http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=225&pcid=41
I have just done an upgrade & going through all my software & checking it's compatibility, so far so good only problem was the Prolific 2303 AT chip driver, I upgraded the driver recommended by prolific but still no joy, eventually found (I think on the prolific website) a driver called PL2303G_DCHU_DFx_Win_21H2_v5.2.0.2_20210720_ML_Driver
Although did not specifically sy it was for Win11 this one worked.
The one recommended for win 11 on their website did not support the AT chip.
Hope this helps.
here is the link I used, scroll down & select win 11 installer
http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=225&pcid=41