I use wampserver (or vertrogo serv) and installed in c:\wamp. I have a file called test.php in c:\wamp\www\test.php. When type http://localhost into browser, it asks me password and username. I cant just pass that. Therefore, i cant use anything. Where this password and username thing come from? I didn't put password anywhere!
What can i do?

The password protection is most likely coming from an apache directive. Refer to the documentation which most likely explains it.

i have ISS runing on this computer as well. Do you think there is something suspicious? because it uses port 80.

I have stopped ISS and started wamp mysql and wamp php. now it is cool.

Yea, if you started using IIS and then subsequently started WAMP, your wamp web server probably didnt start, only the mysql server started most likely. If you would like to run both, you can easly change the port for the apache server in the httpd.conf file. It should be around line 50, you will see "Listen 80". Change that to something like 8080 or 8888 and then restart. The only drawback will be that you will have to access your apache server on localhost:8080 or localhost:8888. The IIS server will be just localhost.

Hope that helps.