When you first start the computer, attempt to boot from floppy... Usually the computer will give you a key to press to do this which will be one of the function (F1-12) keys. It'll say something like, "For advanced boot options, press (Key)" If it's truly a ms-dos/ win 95 boot disk, it should boot with some kind of user interface, for example, "Press one to enter recovery, two to install windows, ect"
If you just want to clear all of the data on your computer for, say, getting rid of it, just format your hard drive by booting the recovery option. usually, while your computer is starting up, it will give you an option such as "Press (Key) to enter recovery" in most cases, you can format from there. Keep in mind you should not see the windows desktop the entire time you're doing this. Another option for clearing data would be to go "Office Space" on the hard drive.
Judging from grammar alone, I'd advise you make sure you're not putting it in a CD drive.