This is basically saying the problem is with the copy-protection on the cd-rom. It is supposed to stop people from stealing the game.
It offers the following solution:
1)Click the following link:
http://www.securom.com/support/custo.../medieval2.zip
2)Save the file to your desktop.
3) Right click the file. Select Extract All. The Extraction Wizard should come up. Keep Clicking next until it says the files have been sucessfully extracted.
4) Go to your desktop. Open the newly created folder called medieval2
5) Right click--> copy the file called medieval2.exe
6) Click on start-->my computer---> double click the c: drive --> double click the GAMES folder--> double click the Medieval II Total WAR folder
7)You should see a file called medieval2.exe right click it select rename. You should see a blinking text cursor in the file name. Move it to the very end of the file name (use the arrow keys) and add ".old" so it looks like (medieval2.exe.old), it's okay if it looks like medieval2old.exe. You may see a warning about renaming a file extension making a file unusuable. Don't worry about it and click yes to rename it.
8) Right click anywhere in the same folder and select paste.
9) Play the game!