Microsoft forbids class actions in new Windows 8 licence

You can't sign away your rights. No matter what they put in their shitty license, you can still pursue whatever kind of lawsuit you want. It's still up to the judge whether or not to go forward with it, but just because a license says something doesn't make it legally valid at all. It's smart for Microsoft to put a clause like that in there because there are judges that might take it into consideration, but by no means is this a get-out-of-class-action-lawsuit-free card.

Oh, by the way, by readying this comment you (the reader) hereby agree to give me $1,000 within 30 days. (See? I can make pointless claims of agreement too)

My point is that legal-sounding words claiming agreement don't necessarily mean anything. What's important is if they stand up in court. I'm no lawyer, but I rather doubt that clause would get them very far. Legal documents are about covering all your bases, not creating magical tomes of inherent power.

This seems to have become a trend in all of Microsoft's products lately. Is this even legal?

Don't buy Microsoft products. Period.