To test that apache ant is installed correctly type "ant -version" from the command line:
C:\ ant -version Apache Ant version 1.6.5 compiled on June 2, 2005 C:\
If you do not see this, you have to check your PATH variable to make sure that ant is in your path. You can do this by opening a prompt and typing the "set" command.
To add the path in Windows: Right click on "My Computer" and find the Environment Variables button. Find the System Variable "Path", and add the path for Ant's bin folder (C:\ant\bin or whatever it is) separating it from other paths with a semicolon.