I put an old HDD in my computer, now my new one doesnt work anymore!!!

[John_828]

Okay so i have a pc with windows 10,
it has no cd drive.
i installed windows on a usb when i got it.

it all works fine.

i found an old seagate HDD,
took mine out, put the seagate in..

it didnt work. just a blank screen with a flashing underscore,

so i took it back out, put my good one back in and...

now everytime i boot up it says :

"reboot and select proper boot device or insert boot media in selected boot device and press a key"

so i press a key and nothing happens,

so i go into bios and see that my toshiba HDD is 1st boot priority.

i tryed unplugging it, plugging it in again,

taking out cmos battery putting that back in,

i've tryed everything.

please can you help me !!! oh gods of technology!?

has the old hdd corrupted my beautiful OS?

and yes my os Drive IS set to boot priority i promise you. (Y)

 

[Barty1884]

A more descriptive title would likely get more interest OP.

Sounds like your boot priority isn't set to the HDD that has your OS installed. Enter your BIOS and ensure the HDD (with your OS on it) is set to boot priority #1 - it'll likely show "Windows Boot Manager" or similar.

If the old HDD has somehow "corrupted" the OS HDD (unlikely) you could boot from the USB you used to install the OS and use the "repair" functionality.