Helping people with computers... one answer at a time.
Every so often the Windows Live Hotmail interface changes and it's easy to miss where certain things went. I'll point you at Reply and Forward.
My Windows Live Hotmail changed a few days ago to a new version; a slightly new look according to them. I can't see how to forward messages and I can't reply them. I do not see any button to perform this task.
Reply and Forward are pretty fundamental, so they certainly didn't disappear.
As the message from Hotmail said, they're just slightly different.
And perhaps in a different place.
The biggest difference to me is that they no longer look like buttons, so that it's very easy to miss them. Here's a picture, with the new location and look highlighted:
If you happen to be looking at your message in "Full view":
Hotmail is in a constant state of change as it tries to both catch up with it's competitors as well as perhaps even innovate with new features. As a result, if you're a Hotmail user you should be prepared for periodic changes, it's just a fact of life.
Some changes are subtle, such as this one, and they can be easy to miss.
But there will be change.