just open the webpage where you uploaded the forum to. Erm, let´s say you uploaded it to a subdiretcory /forum, then you would point your browser to http://yourdomain/form where yourdomain needs to be replaced with your actual domain name.

How do I upload it to a subdirectory?

just create a directory inside your public_html directory

Ok so after I do that what is next?

I phpBB using Filezilla. I placed it in subdirectory phpbb then there is another folder in it called phpbb3. Inside that there is no install.php. There is another folder called install in phpbb3. There is an install_install.php in there. When I type in: www.gamer5797.comyr.com/phpbb/ nothing happens. HELP!

I made a sub directory in the html folder
What do i do now?

Same thing happens to me!
I’m still stuck at this part:

-And yes, you have to replace www.yourdomain.com/forum with the path to where you uploaded it, but that´s not too hard or is it ? So i won´t bother going into more details here, and proceed to the actual installation that is triggered when opening the /install.php file. You will then see the first screen of the installation which looks like this:-

PhpBB is the best free forum software available while vBulletin is the better in terms of security but it comes with a price tag of $160.
Demo : forum hosting

hey i dont know any thing how to creat this plz help me

read the thread, a lot of tips in here.
Additionally i have some phpBB installation tutorial over at my board and also offer free installation service