What is alg.exe?
alg.exe (Application Layer Gateway Service) is a trustworthy Windows core system file from Microsoft. The program is not visible. The alg.exe process provides support for third-party applications, such as IM clients, firewall, RTSP, BitTorrent, SIP, FTP, and Internet Connection Sharing. If the alg.exe file is absent, security protocols will block communication ports and you will lose all Internet connection until you login again or restart your system.
Another way to solve the problem would be opening various firewall ports, which would make the network vulnerable to numerous potential threats. Alg.exe is associated with the Application Layer (or Level) Gateway Service, as well as Network Address Translation, and is designed to increase firewall protection of a network. Although it is not a critical process, clicking End Task in the Task Manager might cause issues with your Internet connection and programs that use the Internet. If you have already disabled alg.exe, reboot your computer to restart alg.exe and everything will be back to normal.
Important: The alg.exe file should be in the C:\Windows\System32 folder. If you find it anywhere else, then alg.exe is a virus, trojan, worm, or spyware! Scan your computer with Auslogics Antivirus to make sure it's not infected.