For clarity, Outlook is still Outlook, it's Outlook Express that's been changed to Windows Mail,

 

Can you open Windows Mail normally from the Start menu?

As penguins says, try opening it from the Start Menu because it could simply be that it needs to be run once to set up the email accounts before it will work through email links on websites.

 

If it won't open it should be possible to reinstall it from the Vista DVD.

Lol.  Yes Outlook Express is gone.  The email program works fine and I don't mind the change.  However, like I said, before the upgrade, if I was on a site and there was a link to an email address, Outlook Express opened when I clicked on it.  Now I get the error message.  I've also just discovered I can't play video from sites even though I went in and assigned programs to play them and my touch pad wont allow me to scroll.  Not so happy with Vista at the moment.

Ok 3 issues here then!

1. WIndows Mail, if it works fine when you open it on its own but doesn't load when you click on links on websites then maybe you need to check the default programs in internet explorer (I guess as you haven't said otherwise this is what you are using?). It's under Internet Options and then the Programs tab, check the default email program is Windows Mail.

 

2. Videos not playing through websites sounds like its also a problem of the program they should play in not being set up properly. Check Windows Media Player has been run and the file associations have been correctly set within it.

 

3. Quite a few people have mentioned touchpad problems try downloading the latest Synaptics drivers from http://www.synaptics.com/support/drive.cfm