Gone are the days where a system freeze would cause your Windows to not load-up properly (pre-Windows 7 with 2009 release date...so +10 years ago?)
You don't need to associate a BIOS Overclock/Reset with a Windows Format/Reinstall.
The BIOS has it's own bit of memory on the Motherboard itself, whilst Windows is installed on a HDD/SSD/M.2 Drive.
So when you reset the BIOS to default settings, it effectively removes all previoulsy saved parameters found on that little bit of memory on the motherboard, and loads default settings (again..stored on the motherboard itself..not on your harddrive or with Windows' installation).
Although saying that, if you have an unstable overclock, and happen to get an unstable Windows as a result, with a few BSODs, you may end up with a Windows that did not shut down properly and yes, in the background, things can get a little messy...
But rest assured 100%, that Windows nowadays is equipped with so many tools to reorganise itself from system freezes/BSODs that are the result of an overclock..so I wouldn't worry one bit about the OS, when dealing with an overclock, at all!
What to do?
Just overclock through the BIOS and run your benchmarks/stress-tests, if it's stable, save those OC Profiles on to USB...if you happen to have a system lock-up from a bad overclock, just change tweak the Overclock settings or revert back to your default BIOS settings in a worst case scenario.
Once you're happy with the OC, just use the Windows you have already installed, as any Windows reinstall, before/after/during overclocking won't make a difference to your system stability.