Need help re-installing printer

HP 720 deskjet printer. Un-installed it via the add/remove section in control panel. Then went to the HP 720 file folder and used the program un-installer. I then realized i should have done it via the un-install feature in the HP file folder first. Now when I try to install my software again via the cd-rom i get a msg sayin the software is currently installed on this pc. Says i have to un-install it first. When I try to un-install via the HP cd-rom software disc, it says there was an error tryin to un-install please insert disc. But i already have the disc in. I cant find any file associated with my HP 720 series printer. My printer doesnt work. Where/how can i locate and delete all HP files/drivers??

mobo: gigabyte ga-7dxr
cpu: AMD 1.4
op sys: winME

Any sggestions/coments appreciated THANX

Joe

No I CANT install over them. I keep getting a message that states the HP software im trying to install is already installed, must un-install first. When try to un-install, get msg saying insert CD-Rom into drive (when it already is inserted).

I found and fixed teh problem tho. Since I didnt un-install it correctly (used add/remove programs instead of HP's uninstall utility) I found an HP file folder hidden in the registry. deleted it and was able to re-install teh drivers. Works ok now.

Joe