Windows 7
apache 2.2.22

After the installation, changing DocumentRoot to E:/WWW in http.conf file made no response. (and <Directory >

I tried rebooting but http://localhost opens the same default index.html page from Apache's server root:
ServerRoot "C:/Program Files (x86)/Apache Software Foundation/Apache2.2/htdocs/index.html"

So I uninstalled Apache and deleted all the file folders in Apache directory except apache2.2/logs/access.txt and error.txt (were not allowed to delete these files)

When I re-installed apache, surprisingly http.conf file still had
DocumentRoot as E:/WWW and http:/localhost still opened the index.html page from Apache's SErverRoot ServerRoot "C:/Program Files (x86)/Apache Software Foundation/Apache2.2"

Can anybody tell me why this is happening?
thanks