Why does my firewall shut itself off constantly - as often as 10-15 min? And then it warns me that my computer is at risk.
There are two causes for this issue:
You have a virus infection and immediately a scan is required to prevent further infection. It's known that viruses try to disable the firewall to spread further or to open ports to unknown hackers. Perform a software/definition upgrade and then scan the PC.
You have a conflicting issue between Windows Firewall or any other application that handles the firewall and McAfee. I recommend disabling all the apps, or even uninstall them and then choose only one.