Hi
Your described method does not apply to Toshiba notebooks.
Every notebook manufacturers supports different BIOS update procedures…
Check this Toshiba US page:
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/downloadDetail.jsp?soid=356848&pf=true
Here you can download the latest BIOS for Tecra 8100
The 4810.25 package needs to be unzipped firstly.
Then you have to check the available files.
There is a readme.txt which describes the BIOS update procedure using the CD ISO file.
Hope I could help