Wordpress 404 error

So I have been working on my website and am now looking to integrate Vanilla forums into it.
I have put all the files into a subfolder in public_html/forum
I then attempt to go to www.mydomain.com/forum to start setup and I get my custom wordpress 404
error.
From reading around everywhere on the internet for the last 7 hours I've come to believe
this might be a .htaccess issue? But I'm not sure, I'm completely new to this whole thing.
Any help would be greatly appreciated.
0
Answers
After searching around for so long I actually fixed it by adding this to the .htaccess document
RewriteEngine On
RewriteBase /forum/
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ index.php/$1 [QSA,L]
RewriteRule ^$ index.php/$1