Why old PC's fail under new or newer Windows 10 32bit or  64bit.? + cures @^@
The installer hard fails, at the get go, or after the install hard failures of PC or just some things fail. (like sound or Lan or GPU is weak)

All things must end. (have an  end)
Myth: Windows 10 should run  on any PC, (false)
PCs have a life span of about 10 years,  but many PCs fail at 5 years old for : (bad batteries are first, then a bad HDD) We test the hdd first.
The reason window installs fail for both 32bit and 64bit are simple this answer."no support" !
The chip maker ended support and when that happened your OEM PC maker can not provide any drivers at all lacking the base line driver from the CHIP Silicon maker.
Reasons to end. (lack of Software drives for Silicon !)
  • CHIP Maker is out of business, the end, RIP. (zero support and no software drivers now) " I like to say Elvis left the building"  (and endless web sites and scalpers selling fake drivers or infected or worse )
  • The maker left this whole business line, the end. (now sells, USB sports hat fans? and beer mugs)
  • The maker decided to end support at XP, Vista or W7, and is their  call (RIP). "REALITY"
  • The OEM maker of PC ended it for their reasons , for the 3 lines above. ( or their CALL).  Many OEM's end support at 10 years old. (common this)
  • Microsoft (MS) ends it when any of the above ends support. (or MS on their own steam ends all support on any PC or CHIP.)  MS may even end support if the PC BIOS is not upgraded , if possible at all.
  • W10 64bit love to fail on PCs older than 2007,  but  CORE 2 Quad CPU with newest stepping does work if upgraded.  (old Core2 iGPU are not supported, see below reasons and cures)
If you get W10 to even install (and will not on any PC with bad HDD or dead or bad batteries)  the "DEVICE Manager" is your clue to tell you which chips are DEAD or crippled . Top fail is iGPU.

Intel ended support on a vast sea of GPU/CPU (GMA graphics by them) GMA-3100 is not supported after W7. (ended in 2007) as in Dead ! (Windows will show up in GPU LIMP mode  called  MBDA
Intel Chipset's  older than Q31 are not supported, or with huge limits. (32bit might run to some extent)
In most cases (32bit) old CORE2 CPU runs great, not the iGPU.  The 64bit will only like the most new CPU CORE2 and newest stepping codes.
Intel only supports FULLY these CPU now (and its GMA and its Chipset) 

W10 32bit for sure runs on more CPU's.
Intel ended 32bit support. (on all new silicon)
Intel does not support the older IGPU, like GMA-3100 located in the CORE2 packaged chip(CPU+iGPU)
MS can block installs based on many factors. (and is very tricky to understand and track across 6 years of W10 evolution)
The MS blocks can be for BIOS version, or iGPU or CPU too old and can get worse in time, MS does delete things  chip makers end support on. <<< this is key fact to learn if using a 2007 PC.
Too little RAM or too slow CPU. clock. 1GHz. min.
MS,  64bit is even more strict on CPU that run and the worse are CORE2 with old stepping, always run the QUAD CORE2 not DUO and run newest intel stepping code.
MS can change the rules at every new W10 build. ( that is why if you are wise buy a used PC (to save money only) with I5 4xxx CPU model numbers. 
Buy Gen 4 up, circa
June 2013, up. do not go lower. (IMO)
In your mind imagine a line of no support walking forward in time.  This is reality. (use this fact to buy used PCs)

In all cases, talk to your OEM  PC maker , if Dell ask at Dell.com
Or just try it and see if it works W10 is always free to try for 30 days. DO IT and see. (use a spare good HDD to test this idea?)

Makers  No longer in business, or left THAT business to make other things, but not this old CHIP or Device.)

Here is another list of defunct computer makers.

If W10  fails for only the  GPU , try a newer GPU card, like GTX-7xx and up.  (Nvidia and AMD both tell you what cards they sell that  run on W10) go there and read.)
My cheap skate ($13) W10 GPU  card list is here,

W10 will love to fail 2007 and older PCs, and for Sound chips and LAN, and GPU,  a vast sea of chips made and no support at all.
If W10 fails reboot the PC 3 times to cause the magic,  Windows self repair mode to run. (even connect up the Ethernet cable to your router to make this magic work 10x better?)

The oldest PC I found to run W10-64 was year 2005  Intel 
945G  D940 up CPU is must. Presler.( a real Intel motherboard) but I had to put in a new GPU card to make it run right. (my tests, alone)(and newest stepping CPU)

Common but very old PC with  chips seen today (relics) and are in the  hopeless list
AVOID like the  Plague.
VIA, SIS or S3  ( dead)
AMD nforce chip set, ended at W7 as seen here (click legacy) clear as day the maker.  Nforce 4 and older ended at VISTA.
Do not buy any PC or motherboard with these junk chip sets.

Version 1.  1-1-2021 (my dead pool page) My record PC for w10-32 bit is 2005. oldest. Dell D520 laptop 945GM ,core2 mobile. (wow)