Reinstalling windows on other drives create windows.old file or not?


Feb 6, 2018
I'm planning to install windows on my SSD, but there was already a copy of it on my HDD, will installing it on my SSD turn the one on the HDD into a windows.old file? Or will my pc just have 2 instances of windows and I will have to spam f11 to select which drive to use?


if u install windows on a drive where windows/program files/etc already exists, it will get moved to windows.old folder
if there is no such thing (another windows is on different drive/partition) then there will be no windows.old folder
u should be able to still have both windows available, in case on boot u wont see that other (old) windows, u can fix it in msconfig by adding boot entry for it


I would d/c the hdd from power while installing win 10 on ssd as Windows will see the boot partition on hdd and use it instead of making a new one on ssd. The problem with it doing this is if you later remove hdd, the ssd won't boot.

I suspect installing win 10 on a PC that already has it installed will likely see 1 of the 2 installs marked as default and PC will ignore the other one. This won't happen if you remove hdd from power before installing as then UEFI bios should know which drive to boot from.

It kind of depends on which format the drives are using.. MBR or GPT. If its MBR, then which boots 1st would depend on boot order. If GPT, it depends which is recorded as 1st in line by the BIOS