Instructions
Download and install WinRAR from the official RARlabs website.
Double-click your "Warcraft II: Tides of Darkness" RAR file to open it in WinRAR.
Click "Extract" from the menu at the top of your screen, then select the directory you want to extract the files to. If you're unsure of where to extract to, right-click on your desktop, then click "New Folder" and name it "Warcraft II." Choose to extract the contents of the archive to that folder.
Double-click "install.exe" to begin the installation. Enter your CD key and choose where to install the contents of the file to, then click "Next." "Warcraft II: Tides of Darkness" will take a few minutes to install to your computer, then click "Finish."