what happens after windows 7 beta expires?

Question:After the windows 7 beta expires, what happens to my computer?Can it to go right back to vista?
Right now I have windows vista. I am planning on downloading the windows 7 beta.
If it doesn't go back to vista, then what am I supposed to do without the vista disk.

Answer:
I would be very cautious that.
The windows 7 beta will stop working on August 1, 2009.When the licence expires, the computer will lock you out.
To continue using your PC, please be prepared to reinstall Windows vista or release of Windows 7 before August 1.
Note that You can't be able to upgrade from the Beta to the final version of Windows 7.

First Make a backup image of your entire hard drive before installing Windows 7.
Then please don't Install windows 7 beta on your main computer. using your Virtual PC or a testing PC.