Assuming that you installed the drivers that came with it, and that the drivers are 64-bit compatible, it seems that either the receiver or the mouse itself is defective. For a new mouse this means that you return it under warranty.
If the driver doesn't work with 64-bit Windows 7 that's also reason to return it.
I installed a new wireless optical mouse.I have a windows 7-64 bit. The install went ok,I check it out and where the other mouse was installed and the message said that this is operating fully. I checked the drivers,and they where install and up to date.It's a Labtec mouse,made in china. The question is, why wont it work? The battery light is on,I push the reset button under it. I need some help with this one.