Playing Caesar II from within Windows XP can be an issue. The following steps will help you get the original DOS version of Caesar II running under Windows XP. If you do not already have a copy of Caesar II go get one then come back here. Thanks to Thomas Crowe for putting this step-by-step together.
 

Step 1: Ensure that Caesar II is Installed
The standard location for the Caesar II install is in a folder in the root of your c-drive named “caesar2″. Confirm that Caesar II is installed to this location, or copy the game files from the CD to that folder.
 
Step 2: Download and Install DOSBox
 
Step 3: Start DOSBox and run the command “mount c c:\caesar2″
This will only work if you have your game files in the “caesar2″ folder.
 
Step 4: In DOSBox Switch to the c-drive by typing in “c:”
 
Step 5: In DOSBox Type “call c2.bat”
Once again, this will only work if you have your Caesar II files in the folder “caesar2″ in the root of your c-drive.

 
Step 6: Select Option 2 (Hit the spacebar)

 
Step 7: Enjoy the game!
Also, please let me know if these steps work for you.