Q: OS X Mavericks

What does it say in the Purchases section of the App Store?

Go to the Applications folder and put the partial download of the Mavericks installer in the trash. You should be able to start over after that if resume does not work form your App Store account.

I know it's free. Anything you download from the App Store will show up in Purchases, paid or not.

Nothing in the Applications folder of the hard drive named Install OS X Mavericks ?

If there's nothing in the Applications folder at all, I would say the download never initiated. As stevejobsfan0123, noted, click on the Purchases link in the App Store and see what options you have for Mavericks. There should be a Download button, if nothing else.