Unfortunately a lot of questions here are about Hardware support as well as shopping. These questions belong on SuperUser. How do we prevent users from asking questions? How can we as a whole improve on this situation?
I'm an SU mod. And well, I suggest that the best way to deal with this is the same way we would deal with questions that belong on SR or HW - close em. Keep closing em.
If its a great and glorious question that causes the heavens to open up and have a single sunbeam shine down on how awesome it is, vote or flag to migrate. If its a horrible question, don't bother, we'll kick it back.
As a SR mod, and having been through the process of helping bootstrap a new site, closures are an essential part of setting the scope of the site. Sometimes you got to set an example.
We really can't prevent them from asking them. Some (a lot of) people simply don't read the rules. What we can do, though, is close the bad ones and migrate the good ones to Super User (if you think it isn't crap, and won't be closed by SU, flag it with a custom flag and ask us to migrate it. We probably will).
I'm not terribly happy about so many of our questions being closed, but I think that it's just going to be a battle this site fights forever. SR fights the same battle to a lesser extent.