8.5.0 was no longer an option so tried the 8.6 version , same result but a different error, now explicitly says "the installation requires to run on a 64bit system for this processor" so you were on the money .   Though doesn't actually help me .  Still no reason as to why now as opposed to the earlier 8.x versions .   It may also be misleading , as it means 64bit OS as opposed to 64bit processor , as i am running 32bit windows 10 on 64bit processors . VMWARE should be alot clearer as to what is minimum spec and also indicate any changes in that in the release notes , as only mention was back at first 8.x version , yet 8.3.0 works perfectly well on 32bit OS . 

Dont really want to swap out my perfectly good 32bit OS for the 64bit OS , thats alot of hassle just to upgrade a minor version of Horizon Client

Oh well, looks like im stuck on 8.3.0 until next laptop swap , maybe a few years away ....  Will thus stick with using my MacBook Air until it too succumbs to a version support issue .

Thanks Baochen1 for taking a look .  FYI no mention of isSupportedArch in the logs in that folder  ,  also last reinstall to 8.6 also didnt seem to create any logs , only ones i found were in a VDM sub folder , and it indicated i couldnt open them (probably wasnt admin elevated , or were locked by app), gave up at that point.