Why is my computer so damn slow???

[Kondziu]

I have a Dell Inspiron 530 with Vista. I downloaded a MS word file which was attached to an email (no viruses, as far as I know). I then right clicked on the icon and renamed the file. A new icon with the new name appeared, and works fine to open the file. The old icon remained on the desktop and will neither open nor delete. When I try to open it it asks what program to use (even though it's a .doc), I pick Word, then nothing happens. When I try to drag it to the recycle bin it says it's no longer located on the desktop and I need to verify its location. It says its size is 0 bytes. Tried restarting, shutting down and booting back up, still there. What should I do? forex robot