strange behavior

Hello, avast now has a strange behavior, after a few hours the computer was on I noticed that the virus definitions were updated on the date of yesterday, so I upgraded manually update failed and asked me to restart, I restarted, but now when I launch the update virus definitions manually or program it asks me to reboot constantly, what is causing this problem?

Download avast! Uninstall utility (here: http://files.avast.com/files/eng/aswclear.exe)and restart your computer into Safe mode. Login in as Administrator and run the utility. After uninstall avast! using Uninstall utility, restart computer and run your registry cleaner or download and install e.g. CCleaner. After installation, run the search for errors in the registry and fix these errors. And then you download a new avast! version here: http://files.avast.com/iavs5x/avast_free_antivirus_setup.exe
Good luck.

I would try a repair first via remove programs then reboot when completed, if still having problems then download the avast removal tool http://files.avast.com/files/eng/aswclear.exe) and the latest version of avast that you are using and save.
Go to remove programs and uninstall avast then reboot into safe mode and run the removal tool for all versions of avast ever installed then boot back into normal mode and install your fresh copy of avast, if not possible to uninstall avast normally then reboot straight to safe mode and run the tool from there.

Hello and thanks I use avast internet security, but I have to uninstall everything from 3 pc, until yesterday everything worked well, from where I download the version best internet security??

http://files.avast.com/iavs5x/avast_internet_security_setup.exe

DJBone

I performed the procedure, I reinstalled, but I just manually launch the aggiornamentodel programa asks me to restart.