Cannot install new version of SafeZone

[REDACTED]

Every time I open SafeZone I get the message "A new version of SafeZone browser is ready to be installed. Do you want to install the update now?"
If I click yes, the next time the same popup appears.
The version I am using is 1.51 running on a computer with Windows 7.
Is there a way to install the latest version?

[Asyn]

Repair Avast:
1. Control Panel -> Add/Remove programs -> Avast
2. Click on 'Repair'.
3. Follow instructions.
4. Reboot.