Windows Vista Internet Browser problems with Vista

My mother's laptop is having some serious problems with accessing the internet through browsers.
She can access skype and windows live mail (her email) but mozilla, safari and IE will not connect to any website, most of the time it simply says it can't connect sometimes it says the website is not valid.

I have tried a system restore to no avail.
I looked around for solutions, and found mention of a winsock program, but that did not work (although that might be because the one i downloaded was for xp)

When i perform a system scan it tells me that the intel matrix storage manager (iaStor.sys) drive is missing (i don't know if that is related). I downloaded a patch from the Intel website that was supposed to contain the latest verison of the iaStor (from a few months ago) but that didn't work either, and another system scan reveals the drive is still missing.

Any help will be welcome, however i am pretty computer-illiterate, so don't use too many technical terms please.