I just read How To Login To An Expired Windows Xp System.

This gave me a nice Windows Vista mini-tutorial.

Notice!!!
I'm not advertising piracy!! It's just a matter of having the rights to access your files, and it doesn't approve that it restores the full function of Windows Vista, and besides

How To Login To An Expired Windows Vista System

1) Login until you go unto the windows where it says that the Windows has expired.
2) Click on the purchase new serial key.
(yehey!!! you got internet!!!!)
3) Rename the address bar to C:\ and it'll open a new window opening the explorer.
(yehey!!! you can access your files!!!!!!!)

That's it!

And apparently from Vista Sp1 there won't be that problem anymore.... they're removing the major shutdown of features if a pirated/unregistered copy is detected, and simply removes your desktop wallpaper and gives you the notifications that your system has not passed windows genuine advantage validation, like what exists with XP now.