I think they probably would but 2 foot thick walls may be difficult. I think yoou shold consider click here If you can position something like this in "Line of sight" between both PC`s (or behind thinner walls!) it may establish the connection.
Otherwise I would suggest either running an ethernet cable from one buildin to the other and connecting it directly to the router or cable again just into the building and attaching the repeater to it. I`ve never had to do this but if FE`s around he has given advice on this type of arrangement before.