Shields won't turn on

I just installed Avast 5 and it is telling me that the mail and network shields are off and to turn them on. When I try to turn them on nothing happens. Can anyone help me please?

did you restart after install ?
have you tried repair and restart ?

For a repair of avast. Windows, Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button from the pop-up window, scroll down to Repair, click next and follow.

did it work ?

I did restart after install and I just did the repair and restart again and everything is working!
Thank you Pondus so much for your advice and time.