a subdomain is already installed, please help how to remove it

[petalshine.com]

hi every one, i got petalshine.com , there is a subdomain i.e. blog.petalshine.com , as i never created it, i want to install wordpress blog on blog.petalshine.com , i have successfully installed it, but when i try to to go blog.petalshine.com , it is redirects to /http://blog.petalshine.com/cgi-sys/defaultwebpage.cgi , please help me that how can i fix this problem
here is screen shot.

 

[cPanelTristan]

When I go to blog.petalshine.com, I see a directory index there and a folder named blog on it. I am not seeing an apache success page. You might try a proxy to see that blog.petalshine.com does work on a non-cached system. A couple of good proxy to use are proxify.net and kproxy.com