There's some guy on this other site that thinks a computer from 1998 can run windows 10 that true?

Nope. The video card would require DirectX 9 support or later, plus the CPU would not have the NX Bit (Intel)/XD (AMD) which has been required since Windows 8. Beyond that, most computers from that era don't go above 526 MBs of RAM which is below the mimimum required for Windows 10. Read this wikipedia article for more information: https://en.wikipedia.org/wiki/NX_bit

I doubt it...

There's no reason why a PC from 1998 would not be able to run Windows 10. It might be slow as molasses, but that's a while other thing.