Answering myself:
MS Sidewinder2 FFB works FINE in Win7
I did not have to install any drivers or anything, just plugged it in. Forces were working at desktop, but not right away in the game. I also had to re-assign buttons and axis in AH, maybe I had just not copied all necessary settings or lost some of them somehow. To fix the force issue, I simply disabled and enabled the forces in AH and moved some individual force slider a bit. Everything was like before in XP
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(Sorry for wrong forum, I suppose this should be in the hardware forum)