upgrade/uninstall/reinstall disaster

ok. i did something imminently stupid.

i tried to upgrade my wordpress blog, and got in a complete mess, so i deleted the contents of the sql database, and deleted all files on my website.

i then tried to install the latest version of wordpress onto the site, thinking that it would just work like a brand new install.

when i go to the /wp-admin/install.php nothing happens. no error message, nothing, just a blank screen.

can anyone help?

thank you