While Steam technically "installs" files, the official Counter-Strike 1.6 on Steam is extremely lightweight (under 500MB). Once downloaded, you can often copy the Common/Half-Life folder to another drive and it will run as a portable application on most Windows systems.
Join the Counter Strike 1.6 community and play with friends or strangers online. With the portable version, you can play anywhere, anytime, without the hassle of installation. counter strike 16 portable no install
🎯 Counter-Strike 1.6 Portable – No Install, Just Play! While Steam technically "installs" files