To start installation, double-click on the downloaded mIRC file.
The following salutatory window will open, click on "Next", to continue setup.
The license agreement requires the registration of mIRC after the expiration of the 30-day trial. Confirm with "Yes" , otherwise setup will abort.
In the next window you can change the setup directory. You should keep the default; C:\Program Files\mIRC. At first install you do not have attent to anything other.
Now mIRC will be installed on your computer. During the installation a progress-bar appears like on the screenshot.
To complete setup, click on the finish button. Did you activate the option "Read mIRC Help file" before, the mIRC Help will appear. The option "Launch mIRC" will start mIRC automatic after finishing Setup.