subdomain issue

Hi，I’ve tried to install wordpress to my subdomain – subdomain.domain.com and I can’t see the blog. Instead, I will be redirected to subdomain.domain.com/cgi-sys/defaultwebpage.cgi

If I install wordpress in a folder named “wp”, then i’ll be able to see the blog but the url of home page now is subdomain.domain.com/wp/

May I know if there is a way to make the home page url to plainly subdomain.domain.com, without the /wp/?

Any guide will be appreciated. Thanks in advance.