Official sources no longer host MainTop 6.1. The company behind MainTop (MainTop Electronics) seems to have discontinued support years ago.
Without this license key plugged into your PC, the software will not open or will remain in a restricted "demo" mode. maintop 6.1 download
search for “MainTop 6.1 full crack free download” on public forums. Those executables are frequently bundled with keyloggers or coin miners. Official sources no longer host MainTop 6
: The installer is available for download on the Maintop Technology Official Site . maintop 6.1 download