I am having the exact same problem. I try to load index.html, index.pl...no matter what it gives me the dialog box to save the file. If I type http://localhost/index.html
then I can see the index.html page but if I type http://localhost
it gives me the file to download.
I have tried the same in different browsers but no use. I have cleared cache...done every possible thing explained but it still doesnt work.
Any help is appreciated.