In most cases, a well designed Microsoft Access query should take only a few seconds to return its data. Even if the database is a very large and complex one, getting the data you need from the query should take no more than a few minutes. If your query runs and runs and fails to return any data, chances are the query itself is problematic and will need to be changed. Before you can make those changes, you need to stop the query without closing the entire Access database.
Place your cursor in the window containing the database. Look for the progress bar at the lower right hand corner of the screen.
Allow the query to continue running if the progress bar appears to be moving. It could be that the query is simply taking longer than normal to run.
Hold down the "Ctrl" key and press the "Pause/Break" key if you need to stop the query. This key combination will stop the query, and allow you to work with the database.