i have visual studio and every time i try to open a web application and vs gives the following error:
The Web Server reported the following error when attempting to create or open the Web project located at the following URL: "http://localhost/WebApplication1'. 'HTTP/1.1 500 Server Error'

if somebody could please help me

You are coding .net? This is the classic ASP area.

try a forward slash after your dir name:
http://localhost/WebApplication/pgeName.xxx

Wind is your friend
Matt