Please note that a patch for BioWin 4.1 has been recently released. The current release version of BioWin 4.1 is 126.96.36.1994. You can download that here.
Also please note that BioWin 5.0 was released in February 2016. If you wish to upgrade BioWin 4.1 to BioWin 5.0, you may do that here.