FileFilter is a Windows shell extension embedded in the windows shell. FileFilter supplies filtering function when copy, move, delete, or compress files and directories. FileFilter can use file types, files' modified time, size and overwriting condition to filter files. The operation is very simple, you simply select files and folders in the Windows Explorer, and click mouse's right button to pop up the context menu, or you can also drag the files and folders directly to the target folder by mouse's right button and drop them, then the drag drop menu pops up, select the operation menu for example, 'Filter Copy'. After selecting the menu, the filtering setting dialog box pups up, you can set details filtering conditions there. Wildcard characters '*', '?', and '#' can be used to compose the filtering file types. There is a file extension browser to select file extensions in the source folder to filtering. The operation history is recorded, repeated operations become convenient.