You see that's where you going wrong lol. It actually doesn't take long to format it's what have you done along the way that is the issue.
For Example;
> All data on another drive i.e NAS, EXT HDD etc
> Use an up to date ISO of windows so it doesn't take long to get latest update.
> Only install stuff you play (games wise)
> Don't customise your machine as much as you want too.
I already have back ups of everything, it's just all the little annoying things and fixes for various things I've had to do over the past few years to get software and hardware to play nice with eachother. For example when I first built it I had to add time delays on boot up to some of the motherboards software because it was playing havoc with some other thing unless it booted after that thing (can't remember what it was now).
It took me ages to figure out what the issue was and find a workaround and I can't even remember what it was now, and I know there have been a fair few other things like that along the way which I've had to implement weird little fixes for for one reason or another.
Another example was a set of foot switches I have setup, I could not for the life of me figure out why I couldn't use the provided software to bind the switches to what I wanted. After a LOT of messing about I figured out that for some weird reason I had to unplug my Logitech keyboard and Razor keypad in order to bind the foot switch keys, but how do you do that with no keyboard plugged in? Well I had to bind the desired keys to my mouse, then I could use the mouse to then bind the keys into the foot switch software.
I've also had some odd behaviour setting up Afterburners OSD, for whatever reason the options I wanted just would not work, no amount of looking online found me the answer but somehow I got it working so I've never touched it since.
My AIO CPU cooler (NZXT Kracken x62) has some weird software quirks as well, you can only control the pumps speed via USB, not via a mobo fan header like most water pumps but for whatever reason the NZXT CAM software always messes up my pump speed so I can't remember how but there was a very weird order I had to do things in and literally never open that CAM software again because the second I did, it just reverted everything back to default. NZXT customer service were less than useless, they didn't have a clue how their own software and hardware worked so didn't have the slightest clue how to help let alone even understand what the problem was.
The reinstallation of Windows is fine on its own as is for my current games (once I've documented all my settings and keybinds). It's not a big issue at all but getting everything back to where it should be will take time and no doubt some headaches because of the problems I'll face.