Mouse issues in certain games

Hello,
I would like some help with a rather irritating problem:
I bought the game "The Witcher 2".
I was thrilled when the game launched without issues, but ...
After the cinematic, on the main screen, I can't move the mouse cursor!
Impossible!
But if I click, the cursor goes to the middle of the screen (so my mouse is recognized by the game)
And there you go, I can't access the game due to this silly problem

So then, I thought never mind, I'll fix it another time, I'll play another RPG
So I bought The Elder Scrolls V: Skyrim
I almost screamed: the mouse pointer was completely immobile!
I could access the game using the keyboard, but I don't intend to play without my mouse ...

Otherwise, all my drivers are up to date, I tried with two mice, in other games like Mass Effect my mouse works perfectly and I've already tried reinstalling and doing fn + f7
or fn + f9
I have a very acceptable setup
PS: It doesn't work on AC4 either :(

So there you go, sorry for writing such a long message but I would really appreciate your help: two great games, and a lot of money wasted like this ...
Just for a mouse, right >_<

Thank you in advance