DreamWeaver and HTTP Error 500

Hello,

I'm Nicolas from FRANCE
and i have a bit problem !!!

Setup : Dreamweaver MX 2004, XP Pro, 2iS.

It's about a Web Site in C#.
It's a actually a page already running in a server and running fin.

But i have reinstall my pc and have a problem with DMX 2004 and the tools :
database connexion.
When i want to view the TABLE, there is nothing... !
When i test ths connexion, there is an error : HTTP 500, Internal Server

Thanx,
Nico !