It sounds like your Class Filter Drivers are missing/corrupt.
I would download and update your BIOS (this should include the class filter drivers), update your DVD drive firmware, and also the WinDVD update for Windows Vista. You can get these from the Toshiba website, here: http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=DL&os=&category=&moid=1598559&rpn=PSAD0U&modelFilter=A135-S4467&selCategory=3&selFamily=1073768663
The 3 downloads I just mentioned, are the first 3 on the list.
Answers & Comments
Hi there.
It sounds like your Class Filter Drivers are missing/corrupt.
I would download and update your BIOS (this should include the class filter drivers), update your DVD drive firmware, and also the WinDVD update for Windows Vista. You can get these from the Toshiba website, here:
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=DL&os=&category=&moid=1598559&rpn=PSAD0U&modelFilter=A135-S4467&selCategory=3&selFamily=1073768663
The 3 downloads I just mentioned, are the first 3 on the list.
Let me know how you get on.
Tim