No. Neither the "fix it".
no need to type in red 
... and don't confuse the MS "fix it" stuff with Avast installer 
... also, depending on what's repaired or what components are added/removed, this very same installer will prompt you to reboot or not... okay no need to write an essay about that ... okay?
The red "no" was for readers to find the short answer easy. About confusing those 2 different actions, I'm not, but the need to reboot is the same in both cases. About some essay, it was to support my statement. Otherwise, it's easy to say whatever without explanation and the user don't know which one of the (opposite) suggestions to follow. I previously wrote the short action in just one simple sentence (no essay): reboot after any of those actions, and only then check the consequences.
BTW, in many (but not all) cases there is no need to uninstall first. Just running the latest stable version of the adequate setup.exe over the current (not working) installation and rebooting will effectively solve the problem, while keeping most of the user's settings. After the reboot, let avast update (and if more problems are find, more optional steps can follow).
