Intel 430TX chipset supports 60/66 MHz FSB.

As dominusprog mentioned, the 430TX only officially supports up to 66mhz FSB.
Depending on the board, and other hardware (not just the CPU) it may or may not be stable at 75mhz.
You can try loosening your ram/cache timings as well as trying other sticks of ram if you have them.
PC 133 with cl2 would be a good place to start.

Indeed there could be something with incompatible memory part. On timings tab in cpu-z (visible when i run it on 66 bus speed) there is JEDEC frequency for 83 Mhz and 100 MHz. No 75 Mhz there. I will try to find different memory module. Changing timings in bios didn't fix the hang.

Whatever timings work at 83MHz should work at 75MHz. You're unlikely to find a module that has a 75MHz entry in the SPD - the table only has room for 2 clock speeds and associated latencies to be stored there.
However, a module with faster chips on it may have better stability with other conditions held equal. Your module could just be going bad. Hopefully you have another compatible module you can swap in as a test.
If you do buy RAM for this board then be careful. Some PC133 64MB modules don't have a compatible chip configuration for the 430TX.
My first encounter with that issue was this exact scenario, when I bought a 64MB PC133 CL2 for my sister's 430TX. It was dirt cheap so I bought the fastest. Problem is since it was PC133, the manufacturer didn't expect it to be used on a 430TX and so they saved money by using denser chips. I don't remember if it had 2 or 4 chips on it, but the board only saw a fraction of the memory.

If you have a multimeter then check your voltages. (Due to lack of accuracy, the BIOS readings are meaningless unless you have a frame of reference, like knowing they used to be different than what they say now).
If voltages are sagging, then that could make the difference when you push it to 75MHz. When you go beyond official spec (66MHz), you may also need better than official tolerances on the power feeding it.

Another way to test stability would be with memtest86. If that shows errors then no need to bother Windows until you get Memtest to pass.
It's interesting you got through the Windows install without issues though. That's an intense enough activity that it's usually pretty error/crash prone if the hardware isn't stable.

I have tested two additional SDRAM module:
32 MB PC66 (date-code on dies 1998) - System on 75Mhz Bus speed boot normal, windows 98 installation passed, crash only during diagnostics (CPU-z, HWInfo, Everest ....), SPD tab in CPU-z is blank when i check it on 66 Mhz fsb.
64 MB PC133 (date-code on dies 2003) -- System on 75Mhz Bus speed boot normal, windows 98 installation passed, crash only during diagnostics (CPU-z, HWInfo, Everest ....), SPD tab in CPU-z shows only 133 MHz specs when i check it on 66 Mhz fsb.

My conclusion to this case is that my motherboard (ATC-5020+) is an early 430TX Atrend design which looks like is some kind buggy. Atrend probably know that they screw up something in it. This explains why they never release any bios update for it. Other issue what i had with this board is that it never POST after applying Bios Patcher (rom.by).

The bright side is that on 66 fsb ATC-5020+ works very stable.

elmatero wrote on 2023-12-22, 08:33:

I have tested two additional SDRAM module:
System on 75Mhz Bus speed boot normal, windows 98 installation passed, crash only during diagnostics

Try SIMMs. I just went through this, two 64 PC133 DIMMs failed in memtest86, 75MHz FSB, but SIMMs passed on all default BIOS settings, 83MHz FSB. MB is ECS P5TX-Bpro 2.0.

Try to disable the SPD check in the diagnostic program, for example in CPU-Z. You need to go to "cpuz.ini" and change the "SPD=1" to "SPD=0".

Prime95 is the way to go for a stability check, or 3DMark2000 in a loop. 3DMark2000 always crashed, if the memory module was broken, or unstable.

With sims memory modules and 75mhz fsb system also hang on SPD test. System is stable on 75mhz and it did pass 3dMark2000 on it. It only hangs on deep testing programs like HWinfo, Cpu-z, Everest, SiSandra etc.
Bypass what i needed was the option that was mentioned above by NostalgicAslinger. With "SPD=0" cpu-z works fine 😀 thanks.
I find out that I can also disable checking SMBus in Hwinfo and Everest 2005 to bypass SPD memory test.

I used to have a Soyo 5EMA+ that would lock up when I tried to run CPU-Z 1.03. At some point I had to clear the CMOS, and after that CPU-Z worked fine! I was curious as to what setting I had changed that caused the problem, but I was not curious enough to go through the settings one by one to find out what exactly had caused it.