[Locked] Need Help Removing

I recently lend my laptop to my cousin for his convention thing when he return it ,there seem to be a new software been installed..

I think its called Sandbox..But when I was going to uninstall it I cant find its uninstaller anywhere even in Program and Features, I ask if he install it but he said he did not ...And if my memory is right I didnt install anything like it in the past week, I only install Chrome and Shikkoku no Sharnoth -What a Beautiful Tomorrow-..
Hope someone can help me remove it...
[spoil]Im really noob in things like this.

Sandbox is part of avast antivirus that runs exe on a protected part of your hdd to run and see if it's badware, viruses or worms... if you installed avast antivirus or internet security.. don't remove.. if not just uninstall avast and it's done.

I see thanks .Forgot to tell that I recently installed avast..