I've tried to look up your model at http://esupport.sony.com/ , but I couldn't find it. Are you sure this is the exact model number?
Anyways, that's what you should do: go the the product support page where you can download drivers and other software for your laptop, and install them.
Update: I've found this product support page:
http://www.sony-asia.com/support/product/vgn-cr35g . I haven't seen 35GN, I wonder, if this is the same machine...