How does restore to dissimilar hardware work?

Hello unfortunately you haven't stated which imaging software you are using.

This outlines what happens when you use Macrium's Redeploy; Macrium Reflect is one which many contributors here use and recommend.
ReDeploy a system to new hardware
v5: How to use Macrium ReDeploy (ReDeploy, Restore, V5)

Re-deploying Windows to new hardware using Macrium ReDeploy - KnowledgeBase - Macrium Reflect Knowledgebase

Here's Aomei Backupper:
Restore A System Image Backup to Computer with Dissimilar Hardware

Ok, let us know how it goes.

OxtailSnail said:

Say i have intel cpu and a nvidia gpu now which i do, And i want to replace everything Motherboard,CPU to AMD one, new RAM, and a AMD GPU. and i got a backup software which supports restore to dissimilar hardware.

my question is this what happens? whats the process like?

They basically automatically update the drivers for the new device but without going through the oobe phase if you used sysprep to remove hardware drivers.

I'm not sure if this still works, maybe @Kari will show up and give advice, but this is how you could do it on Windows 7 with an existing system: Windows 7 Installation - Transfer to a New Computer - Windows 7 Help Forums
It also explains what happens.

Cliff S said:

I'm not sure if this still works, maybe @Kari will show up and give advice, but this is how you could do it on Windows 7 with an existing system: Windows 7 Installation - Transfer to a New Computer - Windows 7 Help Forums
It also explains what happens.

That method is based on generalizing Windows with Sysprep, making it hardware independent. Sadly, that does no longer work as told in that tutorial in Windows 10. You can still use Sysprep to generalize a cleanly installed Windows 10 image before any users and software have been added, but you can't do it on existing Windows 10 installation.

That's why that tutorial never was ported to Ten Forums.

SIW2 said:

Sysprep doesn't work if store apps have been updated.

Sysprep works perfectly on an existing Windows 10 installation, it's just that you can't use the /generalize switch when apps have been provisioned.

Redeploy is not quite the same as sysprep.

In sysprep with generalisation, hardware drivers are removed, and when reinstalled on another device, Windows reinstalls appropriate drivers on first install.

Redeploy updates drivers using the Redeployment Software, essentialness discarding those it does not need i.e. in effect doing the driver removal and addition as one step rather than two discrete steps as sysprepping/oobe does (i.e. removing all drivers first on old PC, then installing them on new PC).
.

Actually, Windows 10 driver handling is so good compared with previous versions, it pretty much works like redeploy automatically anyway.

If you install Windows 10 in a VM, and make an image backup, and restore image to host, it just updates all the drivers automatically in most cases even if never installed on host before.

Of course, if you do not have Redeploy capability, the cleanest solution is via sysprepping but that has its own Windows 10 issues as @Kari says. The slightly dirty solution is to use Windows 10 own driver handling ability.

For a one change of hardware, it is barely necessary to sysprep any more, and even if any issues arise, most can be resolved from device manager.

However if redeploying across multiple devices, sysprep is the way to go (if you do not have Redeploy capability) and it is free as well of course.