There are lot of things those can be done by using the mouse dragging function under Windows 7. Here is a brief tutorial for using the mouse drag function in Windows 7.
Mouse drag function on Windows 7 Desktop
Moving files to recycle bin
Just left click and hold the file or shortcut you want to throw to recycle bin. Move it over the recycle bin icon while holding the left button of your mouse, still the pop up says “Move to recycle bin” :
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The major advantages are, you will not be prompted to confirm the deletion of the file and it is convenient.
Moving files to a folder
In the same way, you can drag any file or folder to another folder in desktop:

Pin to Taskbar
If you drag any program shortcut to Windows 7 Taskbar, it will be pinned:

Pin to the Start Menu
If you drag any program shortcut to Windows 7 Start orb, it will be pinned:

Opening files by dragging
If you drag any file to the program shortcut, it will open with that program:

Mouse drag function inside Windows 7 Explorer
Beside the basic move functions those can can be done in similar way that we have shown you for Desktop; some special things can be done too.
Creating links in Favorites and Library
If you drag a folder or a whole partition to left sided Favorites link, they will be added:

Additional tips by MVP Ramesh Kumar:
Many thanks to MVP Mr. Ramesh Kumar for adding more tips for our readers.
1. If we hold SHIFT key while doing Drag and Drop, we get reversed actions; like, while we are dragging some file or folder content to move them from one folder to other; in this case if you just hold SHIFT key and it will do copy the content instead of MOVE action.
2. Similarly, while dragging some file or folder to Recycle Bin if you hold SHIFT key, it will delete data permanently instead of moving those content to Recycle Bin.
