486DX2

I have a Packard Bell Pack Mate 6419cd. Afriend gave it to me. When I try to access it I get error messages saying I need to install the win 95 boot disk. Is there a way to put in another cpu/board and still use the rest of the cards already inside? Or, will I have to buy EVERYTHING and start from scratch? It is an entire system with a canon inkjet printer, monitor, keyboard,and the mouse. It has CD capability. It also has a floppy drive.
But, no speed, and No Memory to speak of. I want to install a new O.S. but I don’t think I have enough memory for the installation. If I could do that then MAYBE I won’t have to buy all that other stuff. H.E.L.P. P.L.E.A.S.E.