After updating wampserver I can't access to my virtual host (no replies)

Hi,
I updated wampserver and I couldn't access to my site. I asked the forum what could I do and the answer was to import the database that I backed up earlier. That worked well but I set up another site under wamp and this one is Inaccessible.
I really appreciate if anybody could tell me how to sort out this problem and how to avoid it in the future?

Thanks for your time.