Changing where windows boots from?

I installed Windows 98 over my old Windows 98 so I can replace some files, and now I want to make it so my computer boots to the old Windows so I can delete the new one. Any help is appreciated.

if you installed the new win98 in the same exact folder as the old  win98, you can't, as you overwrote the old win98 when you did that.  furthermore, any system files there are already deleted.