How do I deselect using the box select tool? I have read about middle mouse button and some other shortcuts but they don't work for me.
If using v2.68 (revision 57577+), you can do the following:
- Press B,
- Use LMB and drag to form the (de)selection rectangle,
- hold down Shift while releasing LMB.
It sounds like your issue is an issue with the middle mouse button on your mouse. The following steps do not require a working middle mouse button to deselect:
- Go to your user preferences (CtrlAltU)
- Go to the Input tab
- In the left sidebar, check the Emulate 3 Button Mouse checkbox
- Whenever instructions say to use the middle mouse button, you can now use Alt + Left Click instead.
To use box select to deselect use Alt + Left Click and drag.
As described on the Blender wiki:
- B to enter border selection.
- Drag the deselection rectangular using your middle mouse button.