HIMEM.SYS Is missing in Windows 98 SE

I am trying to boot into Windows 98 Second Edition but every time I try to, my PC boots to DOS prompt and tells me HIMEM.SYS is missing. Make sure the file is in your windows directory. And I have not restored the file and I’m not sure how to. And I cannot boot into the desktop whatsoever.

Does anyone know what I could do?