Normally in Explorer, while selecting (non-continuous) multiple files we use combination of ctrl+mouse to select them. By non-continuous,I mean files which are not together else we can just drag our mouse to multi-select. Now Windows 7 has an option where you can select multiple files ONLY with the mouse. For this it provides a checkbox. To enable this feature open Explorer, click on Organize > Folder and search options > View tab > In Advanced settings, scroll down to Use check Boxes to select items and check it. Apply and OK.
Now in Explorer you have a check box to check and select multiple files with just the Mouse.
This is also applied to desktop items.