Nano Receiver Connect Button?

In 2007, I had purchased a mouse (Microsoft Wireless Notebook Optical Mouse 3000) that came with a receiver (Microsoft Notebook Receiver v2.0). I enjoy using the mouse and while it still works, the mouse occasionally won't turn on. That prompted me to buy a new mouse.

I purchased a new mouse (Microsoft Wireless Mobile Mouse 4000) that comes with the Nano receiver. The design of the mouse was a highlight for me, and I kept it over the Wireless Notebook Laser Mouse 6000, which had a squeaky left click. I noticed something strange after taking the nano receiver from the packaging. I noticed that there wasn't a "Connect" button on the receiver or the mouse, unlike my old mouse. I had initially thought of using the old receiver in case I accidentally lost the nano receiver. While I could leave the nano receiver in my laptop, I am not sure if the weight of the laptop will damage the receiver or the USB port itself.

Is it impossible to connect my new mouse to the old receiver?