problems with wireless connection

Hello, Im not an experience Mac user, but am pretty techy. My mother-in-law has a macbook pro and about 3 weeks ago it stopped reconnecting to her wireless after waking up. you have to click to connect even though everything is setup to remember password and reconnect at login, it use to do it before. Today another problem started, its says shes connected but no websites load. I know the wireless works because i tested it with my ipod and windows laptop. I shut down her mac and restarted and like before had to click connect to her wireless because it doesnt do it automatically anymore and it worked. 5hrs later she goes on it again and clicks connect and it says its connected but nothing loads on browser, tried shutting down again but this time it didnt work. I went through a airport help process on the comp and it reset everything and finally connected again. I will find out tomorrow when she tries to use it again if it has the same issues. Any idea what it could be? her airport issues are only getting worse, and now i feel bad that I told her she should spend more money on a mac then on a windows laptop. my wife has a mac mini and i took it over there and works perfectly fine, running same version of mac osX.

here's a few things you can try.

goto the apple menu>system preferences>network. click on locations at the top and select "edit locations". click the plus button and type in a new location. when you got your new location click done, make sure your new location is in the location at the top of the window then click apply. wait a few moments test again. if that doesn't work try this.

go into the macintosh HD>library>preferences>systemconfiguration. take all of the files from this folder and put them ONLY into the trash. if you put them else where they will just copy and this won't work. after you got ALL of them into the trash restart your computer. Connect to your network and test.

if you need help just message me on here.