Malwarebytes & Hitman Pro are good, but be sure to back up or set a restore point before using either. The AVs are good from what I've read here on MT. If you prefer AVG, that is what you should keep, although it's nice to learn about different approaches which is the reason our own Windows 7 has been set up with the default, Defender AV plus Windows Firewall. It is enough. UAC set to default is a safe choice, but be sure not to ignore it's warnings.
Your common sense is the best Anti-Virus protection, & this system is impressively light, free of clutter, & I like that a lot!
A straightforward & useful software I use every couple days, & learned about here, is called
CCleaner. Read about/download it here
http://www.softpedia.com/get/Security/Secure-cleaning/CCleaner.shtml or my recommendation is download & extract their portable version onto an external flash drive
http://www.softpedia.com/get/PORTAB...Portable-Applications-CCleaner-Portable.shtml which is also a great method of keeping your system free!