Question Problem booting already installed windows

[k0RNyx]

Soo my problems started when i bought my new gpu and some cooling fans... When i started to remove things i labeld the order of sata drives conected.. Soo i had my ssd in the sata 6..my1tb hdd in sata 4 and my 500gb hdd in sata 2..when i disconected everything and tryed to do some cable menagment i stared to asemble everything and pluged the hdds in the right order the pc booted normaly but i needed one extra sata power for my switch hub for the case fans soo i disconected my 3rd hdd 500gb(sata2) from the mobo and power and atached the power on my switch hub.. After trying to ppwer my pc it showed me the message to find a bootable drive... In bios the priority its set right and mobo see both drives... The only thing that i can think of is that while i was installing win10 like 6months ago some stuff saved on the 3rd drive that maybe is needed to boot up... I hope you will understand what im trying to say couse my eng its not soo good

 

[Colif]

you suspect the boot partition is on drive 3. Win 10 does things like that to be "helpful", it will put the boot partition on any free space it finds on other drives or if it finds an old boot partition, it will add itself to it.

do you happen to know if bios set to uefi or legacy boot? as that may tell me what format the drives are in (GPT or MBR)

do you have a win 10 installer? its a handy boot drive. If you don't - On another PC, download the Windows 10 media creation tool and use it to make a win 10 installer on USB

lets see if we can fix the boot problem by recreating the files needed
change boot order so USB is first, hdd second
boot from installer
on screen after languages, choose repair this PC, not install.
choose troubleshoot
choose advanced
choose command prompt
Follow this: https://www.lifewire.com/how-to-rebuild-the-bcd-in-windows-2624508

 

[k0RNyx]

Ty for your help but i figured it out... Just booted an exe file from my stick and started the instaler and then it fixed my hdd1 and hdd2 and give the full but priority to the ssd smthn like that now its working... I found later on that the peoblem was that win 10 had some like safe and restore filea in hdd3 and was unable to start without it now its fine... Sry if i took your time

 

[Colif]

no problem, your answer might help others