Windows 10 , install limits , beyond the Microsoft terse statements.           
1G Hz CPU speed, 1GB Ram,  HDD(SSD) big enough (64GB or 128  better) minimum limits.

64bit is limited by the processor present (Gen 4 up) and the HD graphics chip (and even BIOS versions)
W10-64 has many limits on the processor to get all full features and a secure OS.  (W10 has newer minimum security levels that must be met)
64 bit will also fail on some Motherboard, due to wrong BIOS version or will never work ever, lacking any future updates.

32bit is also has limits: (for sure 10 year old PCs and older...)

The first thing that will limit you, will be the GPU present and for sure how old it is.
The GPU makers are many , unlike 2 for CPU's ,  Video chips are just 4 makers now, 2018 (AMD-ATI, INTEL, Nvidia, and VIA) (chip means GPU engine regardless of locations)
GPU makers do NOT have drivers  for Tens of thousands of GPU made for 20 years. Ok, it's not going to happen. Do not hold your breath like mom used to say.
So ask them first.  AMD/ATI chips, Intel HD graphics ,  Nvidia, VIA ,  Just 4 engine makers, for GPU all others are dead, gone, absorbed and killed, or like ELVIS left the building so forget the, wiki has the dead pool list. Here)
Wishing for w10 drivers from dead chip maker is silly at the least (sad to watch)  Intel  page  super good  here on  HD GMA limits.
Dead PC makers here, huge.
Learn that Microsoft can not ask the DEAD for any driver, that be IMPOSSIBLE.
In the case of Intel HD they make the base rules here, your OEM will not write drivers for Intel HD.
The intel HD graphics limits are here, and 32bit on GEN4  is by SKU, (means based on each OEM PC makers rules!!!)

Basically HD 4200 and above.
The newest driver page at Intel for HD Graphics is here.
The 4200 came with the  Haswell CPU GT2 in 2010 all the older HD engine are not supported Ivy Bridge and Sandy Bridge or older,  Intel can change their mind in  nano second but this is true now 2018.
That means 2000 to 4000 GPU is not supported.

The W10 support page for CPU  compliance and other factors , but not covering non Intel graphics engines is where.
AMD-ATI,  and Nvidia has rich support on W10, if  you have their GPU, do not skip going there 2nd, after OEM checks.
If on a Desktop (real ATX spec) you can upgrade to better GPU Video card, easy. (w10 supported and VAST)

The worst case are laptop, due to 2 reason and more,  the laptop GPU is soldered down (99% true on cheap laptops/notebooks) But not my Elitebook.
The other big reason is custom video ram on the mobo, or shared with main memory (cheap Emachine like)  and intel only provided a base driver (kit) and the OEM made many changes to that base.

If you look closely in the links above, Intel is dropping 32bit support, it's days are numbered. (remember 16bit, yeah same deal)
Intel is also dropping w7 support on new processors !!! W7 is doomed by MS  and now by Intel, soon.
Sure w10-32  may  load on many old PC, but is not supported, so if there is problem don't ask them. (ask your OEM sure, it is their design and theirs alone)

Now the facts of life,  and how to point fingers (best is not, until the truth is known, ok?)
Intel did not make your PC nor design it, (exceptions)  your OEM did that, like HP or DELL,  and yes, point fingers there. (if need be)

Microsoft did not make your PC either (it's not an Xbox), and they got  the PnP driver from your OEM, so again, don't blame  it's not their design. (nor is the PnP driver theirs )
So if the OEM says no W10 support believe it,  and that puts the finger pointing  squarely on you. (a fact)
They told you not to upgrade, but failed to listen, ( I too do what I want and replace parts that the OS does not like, using new PCI-e cards or new USB dongle device, killing the other dead in BIOS first)
I can also turn off the onboard GPU chip in BIOS and insert my w10 rated, GPU PCI-express card and W10 is happy to load and run .
But as they say JUST DO IT. (hdd must be good  and I test it first)

But trying W10 costs you nothing with a blank 8GB thumb drive in you repair kit. (we keep a box if those with w10,w7 and linux ready to  boot)
Try it , then if one chip fails to work?,then you  talk to THE chip maker, not the OEM they already told you NO. (in vast cases)
What chip fails, I can not predict that, nor can intel with their odd "some SKU fail" foot notes. (this means some OEMs fail and SKU is the OEM full model number part number )

Knowing this facts make solving problems more easy or avoiding too.

Now my beef with
Why in the world not publish a compliance engine,
Down load it and  ("can_ I_ use_ W10. exe) and run it.
lazy bums, I say.
My guess their answer is " gee it's free to try, so use it to test". OK I lose. (so they saved a fortune at MS, by allowing 30 day trials)

version 1.  12-9-2017