THe games are on the installation media but are not installed as part of the default installation -- If you go to Control Panel - Programs - Programs and features - click on Turn Windows features on or off - in the box that comes up place a checkmark in games (or go into the subtree and select just solitare if that is the only game you want) - press OK and it will install it for you (Note: you might need your Windows disk if the files did not get copied to the HDD )
From Windows 7 Help :
Where are my games?
Games that come with Windows, and any new games you choose to install, appear in the Games folder.
Click to open Games.
If you don't see a particular title, it could be for one of these reasons:
It's an older game. New games automatically show up in the Games folder when you install them. Older titles might not. To add the game manually, see Install a game in the Games folder.
Games are turned off. By default, the games that come with Windows are turned off, in some editions. To turn them back on:
Click the Start button , click Control Panel, click Programs, and then under Programs and Features, click Turn Windows features on or off.
Select the Games check box, and then click OK.
It's a premium game. Some Windows games, such as Chess Titans or Internet Checkers, only come with premium editions of Windows.