Summary: 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.
Related:
Are free email services worth it? Free email services and accounts are convenient and ubiquitous. But free email services aren't the right place to keep your important information.
How can I get the old Windows Live Hotmail back? Windows Live Hotmail changes occasionally and typically there's no going back. If that's a problem, my question is: Why are you still using Hotmail?
Where did my folders go in Windows Live Hotmail? The recent redesign of the Windows Live Hotmail has many people reporting missing folders. It's likely that they're not missing, just hiding.
Article C3559 - November 8, 2008
My reply button disappeared!! Am i the only one who still cant find it?? It was there when i replied a few messages yesterday..
Posted by: Jacqui at December 4, 2008 2:31 AMthe reply and forward buttons are not where you have illustrated in your highlighted pictures, instead I have a blank white empty space/box without the damn buttons???!!!
I am not ranting at hotmail, maybe its my Vista that's acting up all over the place!!!
Posted by: Niz at December 15, 2008 5:51 PMHey Leo, Merry Christmas to U. The button is not shown as marked Red circle as suggested. Where should i find them? I need to click NEW to reply my mail.....help
Posted by: George wong chiong ching at December 28, 2008 6:53 AMI'm missing several buttons including re[ly, send, forward, inbox, junkmail etc. and etc. What can I do? Paul W
Posted by: Paul Winterhalder at January 14, 2009 3:00 PMI am an elderly internet novice. I want any system I use to fulfil clear functional needs. I do not want to have to resort to these forae for help with that which should be bleedin' obvious to those who "enhance" their facilities. What idiot saw fit to change an already satisfactory offering to one that is, to me, a useless frustration?
Posted by: J Nimmons at January 14, 2009 4:28 PMI cannot find how to set the preference to Reply-With-History from the new Hotmail. Could you tell me how?
Posted by: Jim at March 16, 2009 4:47 PMyou guys aren't the only ones... my reply, forward buttons are all missing... got a mac and runs beautifully - get rid of everything microsoft and your life will be much better - i promise.
Posted by: tony at September 4, 2009 8:34 AMhello, if I reply in Hotmail i loose the initial message??? HELP!!
Posted by: Jasper at October 19, 2009 12:39 PMits not there, the hotmail in the image shows the reply button, mine doesnt have the buttons help!
Posted by: bee at October 31, 2009 9:36 PMThis is a great way to get Windows Live IMAP support on your MAC http://fluentfactory.com/mboxmail-for-mac/
Posted by: tomb at November 3, 2009 2:30 PM