Internet problem

Hi,

I have a 3G modem, HSPA-500HU
and the problem is that i can't connect to the internet, my firewall and all other things are ok, because it used to connect.
when i dail up, it gives me "dail failed, do you want to retry?"
I went to the service provider and there was no problem what so ever with the modem or their servers.. so the problem is with my pc..
i have a dell inspirion 1012, win 7 ultimate

can someone help me ??

Have you tried a restore point prior to when the problem began?

Otherwise I would remove the card and go into device manager and remove the drivers for it. Even install and run Driver Sweeper to make sure it is well cleaned out. Then reboot and try installing it fresh.