Before you take it to the mechanic take a look at this thread: http://www.freerepublic.com/focus/f-chat/3504756/posts
It outlines a Microsoft update that broke networking on several machines. If you have a way of downloading the update fix (warning: it’s over 500meg!) you can get it here: http://www.catalog.update.microsoft.com/Search.aspx?q=KB3206632 and save yourself some scratch.
thank you for that!