Wanted to share something. I used:
Team Foundation Server on OURSERVER <no-reply@domain.com>
For the email address (as I hate getting emails with no good name). The setup halted with the web service error (28100)...
The setup program shoved the characters < and > literally into the xml web.config file.
Modifying the web.config for the /services app and removing them fixed the error and allowed the setup to complete.
Cheers!
-Sean