I used a website called GOOGLE to find this for you.
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=DL&os=&category=&moid=1467727&rpn=PSAA8U&modelFilter=A105-S4284&selCategory=2756709&selFamily=1073768663
Thank for your help
This driver is for vista not win7 dont work