What is the simplest way to associate mailto URLs with the hotmail web site?

Family computer support question: I have a relative who's a hotmail user. I'd like to setup his machine (IE 8 Vista) so that when he clicks on a mailto URL it opens a new page/tab for composing mail in the normal hotmail mail composing window. Introducing a new progam like Windows Mail is way too complicated. It needs to be dead simple. Do I need "Live Mail" to do this? Or is there something even simpler than that?

Officially Windows does no longer support "mailto webmail", but that doesn't mean it cannot be done.

i'm using Gmail as my default client in Windows 7 with IE8, here is what i did:

download and import this registry file (credit to limneos at sevenforums.com), which is written with Yahoo! Mail in mind.

go to Default Programs > Set your default programs > Internet Explorer > Choose defaults for this program, under Protocols MAILTO is now available, check the box and Save.

right now, all mailto links will open Internet Explorer with Yahoo! Mail/Compose, to change this, open the registry editor and navigate to

HKEY_CLASSES_ROOT\Yahoo.Mailto\shell\open\command

double click the default value, the following part (url) of the value data has to be replaced:

http://us.mc01g.mail.yahoo.com/mc/compose?.rand=947383854&to=%1

for Gmail, i'm using this URL instead:

https://mail.google.com/mail?extsrc=mailto&url=%1

for Hotmail use this URL:

http://hotmail.msn.com/secure/start?action=compose&to=%1

voilá, Hotmail as default email client in Windows.

p.s.: i have tested Hotmail as default email client in only in Windows 7 & IE8, but this workaround should work for Vista just as well. i don't use Firefox, but i'm pretty sure this can be done with FF as well if you change the value data of the default key accordingly (FF may require %s instead of %1 at the end):

C:\Program Files\Mozilla Firefox\firefox.exe http://hotmail.msn.com/secure/start?action=compose&to=%1

of course you will have to associate FF with the MAILTO protocol.

note: as usual, you should backup the registry before making changes.