Hey, you and me both. I have a Vista Lenovo Thinkpad and the Microsoft Bluetooth mouse (the white one without any adapter). I find that if I leave the mouse on and then close my laptop, boom, the mouse doesn't work if I turn it back on. This is absolutely frustrating, as my macbook has no such issues.. (hopefully BT will be better in the future).
But, this is what you want.. some sort of easier solution. I have a little switch on my computer that turns off and on the wireless and bluetooth radios (this might be a switch or a Fn+Key for you). I find that if I turn it off then on, it will cause the Bluetooth to cycle and my mouse will work again.
It's a whole lot easier than reinstalling..
See if that works.
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I've got spurs that jingle jangle jingle.
As I go riding merrily along.
And they sing, "Oh, ain't you glad you're single?"
And that song ain't so very far from wrong.