Turn on your computer. Insert the program's installation CD into the computer's CD drive. Usually an installation window will open automatically after a few moments.
Follow the directions in the installation window. Each program will have slightly different steps, but if you are not an advanced user, you can leave the default options as they are and click Next or OK in each window as it comes up. It is normal for one of the first steps to require you to pick an option stating that you agree to the program's Terms of Service, End User License Agreement or similar before you can continue with the installation.
The final window will have a button labeled Install, Finish, or something similar. Click it, and the program will begin installing on your computer. If additional windows open asking if you trust the publisher of the program or otherwise verifying whether you want to proceed with installation, click "Yes" or "OK." These are a safeguard to keep malicious programs from installing themselves without your knowledge, and do not indicate that your program is in any way unsafe or untrustworthy.
When the program is done installing, a final window may open to report that installation is complete. It may have an option to run the program immediately, which you can check or un-check depending on your preference. Click "OK." The program is now installed. As long as you keep it installed on your computer, you can run it any time by double-clicking its icon.