frontpage decription

How would u be able to decript a password from "_vti_pvt/service.pwd"???

eg.
http://www.victim.com/_vti_pvt/service.pwd

# -FrontPage-
victim:v1ct1m

I'm probably going to get flamed for helping you, but...
It looks like Altered-DES, "UNIX-style".
Try downloading a passwd cracker like "John The Ripper" and put each username : password into the password format like:

username : password : 0 : 0 :anything here : /bin/bash