connection problem

XP Pro, SP3, current updates, ZA, A^2, Lenovo T60p Dual CPU - 2.1 ghz, 3 Gb computer memory, 3 cent operator memory

Why?

Everything about networking on my computer says "Connected." Inside the router, on the available connections list, in the Network Connections window/dialog, wireless connection, Internet connection...

But no internet app will work.

Once I got it back by rebooting. Once by shutting off the modem half a minute, but why was everything showing me all these connections if the modem wasn't even working???

Turning off _everything_ for an hour seemed to make it go away - this time.

Is there any kind of (functional/functioning) modem diagnostic available?

(By that I mean something that actually does the job, not some half cocked OEM utility.)