Today I installed a retail version of Half Life 2 (legit version) on my computer. I decided that I should put it on steam to make my account a premium version (an account that has a game that is not free on there). However, I try to put in the code, but it says "Installation of Half-Life 2 Retail Standard is required before installing. Please insert your Half-Life 2 Retail Standard CD/DVD into the drive and select "install" from the autorun menu."
However, it doesn't work despite it already being installed, and it does not work during the installation process. Whenever I enter Disc 1 in order to install/reinstall the Half Life 2 Retail Standard, steam instantly shuts down. WHAT DO I DO