Hi, my Avast 5.1.864 is missing Sandbox!!!
Before this new version, when I clicked on the icon IE8 show options for browse in SandBox… now, version 5.1.864, missing this resource.
Why???
High Wilkens: Don’t know if you have already tried this but Start with the simplist first.
Have you tried a ‘Repair’ of Avast. Control Panel/ Add and Remove Programs/ Choose Avast then Change/Remove, when you get the list of Options, choose ‘Repair’
Let us know how that worked. 
It depends on which version of avast! you are using as you do not show that information.
It looks like you are Portuguese and need help in:
avast!WEBforum | avast! support forums | International zone | Português
http://forum.avast.com/index.php?board=27.0
You need the help of Tech:
http://forum.avast.com/index.php?topic=67349.msg567711#msg567711
Sandbox is there. It’s called “Process Virtualization”.