I am running on Windows 7 64bit on a Samsung S3511. My MS Bluetooth Notebook Mouse 5000 v1.0 always stop working after hours of use. I simply could not get my laptop to pair with the device this time. When I try to add it again, everything seems to work, but then no response from the pointer, and after few seconds the device disappear from the list of bluetooth devices. 

Here's what finally solved it for me:

1. Disable "Power Management".  Click on Bluetooth icon, select Open Settings.  Go to Hardware tab, and select Broadcom BCM2070 Bluetooth 3.0 +HS USB Device.  Click Properties. Go to Power Mangement Tab and unselect "Allow computer to turn off this device". Reboot!!!

2. Go to Start, type services.msc, then double click on Bluetooth Support Service, select Automatic. Go to Log On tab and select "This account" and type in Local Service.  Delete both passwords. Reboot when done!!!

4. Go back to Bluetooth Setting and ensure that you select "Allow Bluetooth device to find this computer" in the Options tab.

5. Add the mouse device again, this will load device drivers and install.

Hope it works for you too!!!