What error are you getting, exactly?

Not 100% sure about Windows 98, but Windows 95 does not need an FPU and will run on a 486SX, which is basically what you have there. If Windows 95 is giving error, your root cause is something other than lack of FPU. And it's highly likely the same applies to Win98 - I've even seen Win2k running on a 486SX...

Not sure what a divide by zero error
Means without context

The error was Runtime error R6003 integer divide by 0, but now this is embarrassing, I tried again to get the exact error and the point where I got it, and win98 installed ok, even worked afterwards no problems. Obviously with /NM switch.
I guess perhaps was an power issue. Now I'm reinstalling because even thou it installed and worked, the IDE controller was not, no drive in device manager, witch was very weird, said C drive was working in DOS compatibility.
Set in bios IDE in legacy mode to see what it installs this time. The only drivers I found for this SoC is LAN and VGA, no mentions anywhere for IDE drivers.
If you have any other suggestions for this CPU/SoC, please advise. Also, what is the last version of DirectX I can install on a non FPU CPU, DX9 will not work, 6.1a comes with 98 by default, perhaps 7 or 8. Thanks!

Runtime error R6003 integer divide by 0 is an error from the Microsoft C library, and is notorious for popping up when running certain old games on faster CPUs. But if you're already getting it when installing Win9x, that's not the problem. Second cause is data corruption. That could point to bad storage media or bad RAM. That matches with behaviour changing when messing around with IDE mode. However I'd definitely recommend running Memtest86 overnight to double-check your memory is OK, as if it's not it can cause ongoing stability and corruption issues.