hello - Im convincedmy hard drive has failed - - No boot disc.  Its happenned a few times and have always been able to get it to a chkdsk and recover...Cant even get that far this time

So, im potentially left with replacing the hard drive.   My question is I have a Dell Desktop 5100 which came with Windows 7 preinstalled - but later upgraded to Windows 10.

If I put a new hard drive in - how do i recover the operating sytsem side of things - because in the model I have I was never provided any Windows recovery media....