Clean-Install needed

I think I already know the answers to my question -- but I wanted to check with the Experts here before I attempt this and ruin a working PC. (NOTE: This is my wife's PC, and she will KILL me if I mess it up!)

I have an old Win10 desktop (upgraded from Win7) that is NOW failing the recent KB update over and over -- and I want to do a clean-install from the latest Win10 media.

There are some catches, though ...

First, the PC is running 32-bit and I want to replace that with 64-bit. It has a 64-bit processor and is only running 32-bit because the previous motherboard failed and I migrated this to a new motherboard using Macrium Reflect and, at the time, did not want to go through the grief of reinstalling. So, this PC is activated using Win10 -- but if I install 64-bit install, that should still activate OK, right?

Second, the PC already has two physical drives in it, with no room to mount a third, so I want to put the new Win10 install on the same SSD as the existing one by clearing out a data partition and making some space. So, when I do that, realizing that the installation will update the boot information in the existing System Reserved partition (it is using BIOS, not UEFI), nonetheless, it should not touch the existing Win10 32-bit installation, right?

My thoughts around doing it this way is to have both the old 32-bit and new 64-bit installations working for a short while so I can carefully migrate stuff from the old to the new. And, yeah I know that I will have to reinstall all the apps again, but I'm more concerned about being able to migrate the settings and data.

Once I get the 64-bit version working OK, I will erase the 32-bit version and recover the disk space -- as I have an MR image of it to keep.

Since this was an Upgrade, and I have an image of the Win7 32-bit installation, should I go the extra mile to restore that and use it to generate the genuineticket.xml file, just in case the activation of the 64-bit installation does not take?

And finally, since the FCU comes out in a few days, can I use the ISOs I already made of build 16299.15 (from my Insider machine) to do this installation? Or, should I install from the last release and just upgrade on the 17th?

Anything else I might have missed?

Activation doesn't care whether you chop and change between 32 or 64 bit. There should be no issues there. However you can not upgrade a 32 bit to 64 bit or vice versa. You have to clean install to make the change.

It seems pointless to clean install now, only to upgrade in a few days time. I would just wait, and that means wait until the official consumer release appears. No point guessing whether the latest Insider build will or will not be the same as the final release.

Do it right and do it just the once :)

(and if you have only 4Gb or less then the 32 bit version could win out at the end of the day. You gain in some areas and lose in others.)

Thanks ... but I need to know if installing a 64-bit version of Win10 to another partition on the SSD is going to mess with the existing 32-bit install in any way. Because if it is, then I need to find a way to install to a different disk.

Others have tried dual-booting 32 & 64 bit, apparently it can be done. here's one...


Dual boot Windows 10 32 bit and Windows 10 64 bit

Personally I'd avoid it, my backup plan would be to make an image of the existing 32-bit system with something like Macrium Reflect (free) as your 'fall-back' option then do a clean install of 64-bit.

BTW, I run 64-bit in 4GB of RAM with no apparent downside. Even seems to work fine when I test using it without a swapfile (though I wouldn't recommend that, I was just curious as to how it would perform).

It's not my intention to keep both the 32-bit and 64-bit versions around for a long time -- just long enough to migrate everything onto the 64-bit install.

You shouldn't have any issues dual booting temporarily. I've set up computers that way when the old Windows got corrupted. It's a good idea to turn off Windows 10 Fast Startup when dual booting:
Turn On or Off Fast Startup in Windows 10 Performance Maintenance Tutorials

Personally, I like to just turn off hibernation with:
powercfg -h off

which also disables fast startup.

Hey folks, thanks for all the advice!