Need help installing network adapter drivers!

So Windows XP is working but I can't get my cable internet to work with it.  I don't have any network adapters for some reason adn I don't have a disk with driver stuff to put on.  I tried downloading the network drivers off the site here but when I put them from a flash drive to my computer, it won't run them as applications as it should.  it just asks me what I should open it with.

I need to figure out how to make the internet work!  I can't get a LAN connection, because my ethernet port is not being recognized I think.

BTW the desktop is an XPS 400