Instructions
Mount your Starcraft II ISO file to a virtual drive. You can use free software such as WinCDEmu or a free trial of PowerISO or SlySoft CloneDVD.
Run the virtual drive's autoplay feature. You will see the ISO available in your "My Computer" window under "Devices with Removable Storage." Because the ISO is mounted as a virtual drive, Windows thinks that the Starcraft II DVD is actually in the computer. Simply double-click that icon to start the autoplay.
Allow the game to install itself and connect to the Internet to update automatically.
Open the files on the virtual drive. You can get into these files by right-clicking the drive icon in the "My Computer" window and selecting "Open."
Find and run "Razor1911SC2_COPY.exe" to finish the installation.
Run "Razor1911keytro.exe," also on the virtual drive, and press "F2" to activate the game. The single player version of Starcraft II will now be unlocked.