Use one PC to repair another

Can you direct connect a working Windows 98 PC (with a CD Rom drive) to a non-working PC that has no CD Rom drive, and, use the one to repair the other?

Basically, we want to use the working PC as an external CD Rom, to load the Windows O/S, since the non-working PC does not have one.

The non-working PC starts up and gets to the point of “boot up in Safe mode”. When you attempt to do so, it states “Registry error” and “computer will reboot now” and will not boot up in Safe mode. You cannot exit normally. You can get to the DOS prompt.

We have no idea what is wrong as it came to us in this shape.

Does anyone have a suggestion, perhaps an application, that will enable us to get this PC working again with a Windows O/S?