Problem with Dell Dimension 2400

 I have a dell dimension 2400, and it was running very slow so i thought by removing some applications, the desktop would run smoother, i downloaded  a thing called uninstall unwanted apps, and when i checked on top , i removed everything , even too the system restore partion, which doesnt work now, i rebooted my computer, and than turning it back on, the whole screen was black, and blank , i pressed ctrl + alt + delete and than whenever i got the taskmanager i saw that everything was still their but when i tryed opening it, it was normalizs.dx need to reinstall, so i bought the windows xp 2000 disk and i have the other parts of dell reinstallition disk. i have tryed F1,F8, F11,and F12 and still nothing i havent been able to fix it, it starts up and its still black nothing on screen. When i tryed booting into safe mode also blank/black screen and rebooting hasnt helping either.  So im not sure, if their is a way to reformat the intire thing now, and start a clean set up , or what to do,  i need help, please if you have any solutions to this email me at Email id removed per privacy policy > thank you