You cannot compose or reply to messages in Exchange OWA using Internet Explorer 7 or 8

After e.g. upgrading to VISTA or Windows 7 which comes with Internet Explorer 7 or 8 you're not able to use your Exchange based webmail. If you hit Reply or New - you'll not be able to type anything, you'll see a red cross in the message body. That was done, of course, for your own good - to make your email more secure. Don't you get it? If you don't use email - you have less chance to get a virus out of it, right? Ironically you can still use Chrome or Firefox.

There are 3 ways to fix the issue:

1. Use another browser , e.g. Chrome ( most preferable one :-) )

2. Fix your browser. This is not recommended (you don't want to fix everybody's browser do you?)

http://www.microsoft.com/downloads/details.aspx?familyid=b769a4b8-48ed-41a1-8095-5a086d1937cb&displaylang=en#Requirements

Use it at your own risk - I haven't tested it.
Here are some explanations:

http://blogs.msdn.com/ie/archive/2006/06/27/648850.aspx

Here is another fix , but it only works with Exchange 2003 OWA (Exchange 2000 doesn't have "Email security" under "Options")

http://mustech.net/2007/02/20/windows-vista-webmail-owa-fix-for-internet-explorer-7-five-step-fix

3. Fix your Exchange server.
The hotfix itself never appears on Windows/Microsoft Update - this is not a bug, this is a feature, right :-)?
http://support.microsoft.com/kb/911829

You can download the hotfix for Exchange 2003, but if you have Exchange 2000 then you can call MS back for support and they gladly provide you with the hotfix for Exchange 2000.... for additional cost of course. Be prepared to pay at least $300 upfront. You can also download it from 3-rd party at your own risk here:
http://thehotfixshare.net/board/index.php?autocom=downloads&showfile=3638