Hi
I assume you’ve got a Tecra S11 PTSE3E
The BIOS for Tecra S11 is compatible with Tecra M11 and Tecra A11
On the Toshiba USA driver page you can find all BIOS versions…
The BIOS for Tecra A11-S3541 PTSE3U series should be compatible with Tecra S11 PTSE3E series.
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/home.jsp
Choose Tecra A11-S3541 and download the BIOS version you want to install.
Unzip the package and check the readme.txt
There you can find info how to flash the BIOS using tradition BIOS version.
I think the win-based BIOS version would not function because you’ve got already the newest BIOS version installed.
But in my opinion you should not downgrade the BIOS because it looks like many fixes has been added to the new version…