I presume that you have a router that you use to connect via wireless? If so, get an ethernet cable, plug it in and do sudo apt-get install ndiswrapper. Rather than have people on this forum try to guess what compile errors you have, i suggest just googling for the error. For something as fundamental as a compile error of ndiswrapper, I guarantee that countless other people have had the same problem.
Also, when you downloaded ndiswrapper from sourceforge, did you not notice the list of pre-required programmes? Download all of these and install them and then try and install ndiswrapper, but the best option is find a router and plug in the ethernet.
Also, putting the subject of your post as "What am i doing wrong?" is not very productive. Next time be more specific......
