can not reinstall MSDE

I installed Microsoft Project Central on my Win2K machine some time ago and at that time we decided not to use it, so I uninstalled both Project Central and MSDE using the “add/remove” program. Now I wish to install this again and I can not, the software says “You can not use the install now setup since MSDE is already installed on the machine”. I know it is not because I removed it using the windows “add/remove”. Does anyone know how to make the program re-install MSDE or remove MSDE properly?Thanks