internet connecting

here at home I can wifi, but if I go to a public place I can connect, except internet explorer wont display web page. here at home i wifi off my nieghbor suddenlink cable internet, set for home, i can wifi off my sis AT&T u-verse, set for work. my mother is in hospital having test done for the whole entire week, the hospital has wifi and when i connect to it, it says internet access, but no web page will display. even my side bar gadget for temperature wont even display correct temp.
my sis can browse the web on her HP laptop but I cant on this crappy acer. i have the Atheros AR5007EG b/g with latest driver and microsoft miniport with latest driver. here at home signal is wireless N, hospital has wireless G.

The connectivity issue has nothing to do with the brand of notebook computer you're using.

Have you checked to see if the hospital's wireless connection needs a login and password?

Have you checked your wireless settings in the Network and Sharing Center?

have checked, tried resetting, and nothing. even added it to the list of networks. set it to connect automatically, manuelly and still nothing. in taskbar show connected with exellent signal, move pointer over it, says internet access, but when i click explorer it comes up saying explorer cant display web page and has the trouble shoot there, run it and it says its configured correctly, dsn unreachable. any web page is explorer cannot display webpage. i also have a sidebar gadget thats for networks and it shows no connection,i dont run the sidebar cause it has driver issues and stops responding.
this acer aspire is no longer acer, i dont have any of acer software on here, this aspire came with vista home basic, i tried upgrading to vista home premium and couldnt cause they took out some important files i needed for upgrade, also the malicious software tool removal we get once a month, it attack acer software and threw this sucker in a loop where it acted like it had a virus. so i bought a OEM system builder dvd and installed on here, had to use the emachine e 620 win7 drivers, cause the e620 is acer replacement for the aspire 5515. if you had acer upgrade your aspire 5515 they gave you back the emachine e620. im running the 32 bit win7 since that is what acer had it set to.
i had same issue when i tried wifi-ing from the public library, but i uninstalled the atheros from the device manager and rebooted and had explorer then, tried it at hospital and no explorer. every thing i tried doesnt work even though it says internet access.