my experience is somewhat different. I own a Dell Inspiron 9400 running Windows 7 64-Bit.
the attempt to install and use a Microsoft Bluetooth Notebook Mouse 5000 was a real pain. at first, I tried to pair the mouse, it happened but I could not use it, no cursor movement at all. Windows 7 uses Dell Truemobile 355 Bluetooth + EDR driver version 6.1.7600.16385 here. then I tried the Dell Vista 64-Bit driver, which downgrade to 6.0.1.3100 but the setup routine upgraded the bluetooth firmware to version 2.16. once installed, nothing happened, I couldn't even pair the mouse. I tried to install latest WIDCOMM driver, with no luck, same effect, no pairing at all.
then I revert back to a previous Windows state through System Restore and I restarted with the mouse pairing pass. it paired, and now the mouse works! however, after a couple of days working with it, I stated it sometimes stops to function then it runs again after some minute. sometimes, instead, the wheel stops working. in a word, it's unstable. I'm not alone, I read other posts like mine across various forums. I cannot test the mouse with other notebooks, but I don't really think it's a mouse issue.