Can't connect to the internet

I have an Inspirion 6000 with Intel Prosett wireless. The problem I am having is I cannot connect to the internet via my wireless connection. If I load AOL, browser or dialer, and connect via dial-up(which I hate to do) then I can view with Mozilla or Internet Explorer, but as soon as I disconnect the wire..I am toast! The little "radio signal/attena in the taskbar" always pops up as soon as I log on, it is green, full strength and displays "connected to lynksys at 55 mpbs" which has always been the case. but as soon as I click on my browser...the bottom of the screen displays "looking for aol(my homepage)" eventually times out, and dispalys the usual.."cannot load page...."A few days ago I couldnt even connect dial up. AOL  kept displaying the message "modem is  being blocked  from connecting. I opened my task manager and ended all of the nonessential programs and was able to dial-up. I even reinstalled AOL.. But still no wireless viewing capabilities. I hate dial-up, and AOl Browser of course b/c it is atrociously slow, and wants to take over the world(excuse me,my computer). Please help me get my wireless viewing capabilites back! This problem started 3 days ago.. i am completely lost about what to do...Lastly I live in a Apt complex in which the wireless(router) that is transmitting the signal "free for the tenants"..I have no access to nor will I ever! But it has always been and probably will continue to be unsecure! So whatever the problem is hopefully is on my end only and can be fixed.  Thank you , in advance!