Wifi problems with AOD255E

I use the wi-fi at my local library, after my allotted time is up on their broadband computers. For the past month or so, my netbook has been giving me problems.

What happens is I'll be on a site and all of a sudden, I'll get a notification at the bottom of the screen saying the site isn't responding, and to refresh the webpage. This can take forever, and I'm not a very patient person. Whenever I run the troubleshooter, it says it can't detect any problems. Also, it often takes too long to shut down, and I get so impatient--or short of time--I have to hit the power button, which means having to boot up by starting Windows normally the next time I startup.

I have spoken to the library staff about this, but they don't seem to be very motivated. I would like to have home internet, but our satellite company only offers TV-phone-internet bundles, and we don't need a house phone because my roommates and I all have cell phones. I've tried a hot spot provided by one of my roommates, but that's just as slow and wonky as the library wifi.

Is the problem the wifi or the computer?

My netbook identifies me as a casual user, and I've cleaned my files twice in the 5 years I've owned my machine. I also have excellent protection (VIPRE Internet Protection), and haven't had many problems with it, really. Any help is appreciated.