maybe it has changed fairly radically, but it's primary purpose has always been to define the contents of your Computer, both Hardware and Software, which one might do just after you bought the thing, to check that you got what you paid for, and at occasionally, at a later date. if you had forgotten to save the reading or were considering in upgrading a part.
I know that it lists all the Windows Updates and the latest version checks that list against the latest available.
But surely Secunia does that better. click here as does the M$ Update Site