How can I reduce MS Access file size after deleting the data?

I had a huge MS Access file (.accdb) with the huge data. I deleted some of the unneeded columns and saved the file, but the size of the file did not change. What can I do to reduce the file size? Can you tell me what's wrong?How can I reduce MS Access file size after deleting the data?
From MS Access HELP File:



Compact and repair a database that you have open

Note If other users are also currently using the database file, you cannot perform a compact and repair operation.



Click the Microsoft Office Button , point to Manage, and then, under Manage this database, click Compact and Repair Database.

Compact and repair a database that is not open

Note If other users are currently using the database file, you cannot perform a compact and repair operation. While you run the compact and repair operation, no one can use the database file.



Start Access, but do not open a database.

Click the Microsoft Office Button , point to Manage, and then, under Manage this database, click Compact and Repair Database.

In the Database to Compact From dialog box, navigate to and double-click the database that you want to compact and repair.How can I reduce MS Access file size after deleting the data?
Tools - compact the file.