Scanreg Dell Dimesion 2100 Computer

I have a beautiful Dell Dimesion 2100 Computer that give me a error message upon start up that the registry is damaged and tell me to run scanreg to restore. Well when I restart computer it takes me to safe mode, but my problem is that when I get into safe mode I see a gray screen and the words safe mode in the corners and nothing else there is nothing that, I can click on to fix it so my question is how do I run scanreg if I can’t get the computer into safe mode where by I can make the changes. need here I went to Dell site and the information they gave me assumes that you get to safe mode and can make the corrections. It doesn’t give other options if you can get to safe mode. Let me know if you can help me, thanks .

Nathan