Windows 7 - Reboot and select proper boot device

My second windows 7 apocalypse in three weeks.

These are the steps and links I followed in order to not format (again) my system:
1) Ensure my main hard drive works properly
I disconnected the others hard drives (I have three) and I searched my main hard drive in BIOS.
The HD was there and was the first option to boot menu.

2) Try windows 7 gui repair tools
I booted from a win7 install DVD and tried to use all repair options. The problem was that my previous win7 installation was not recognized.

3) Try windows 7 command line repair tools
One of the repair win7 options is to open a DOS prompt. There I put the following commands:

bootrec /FixMbr
bootrec /FixBoot
bootrec /RebuildBcd

The first one was successful, but the other two prompted "element not found"

4) Reactivate main partition (https://aitorlozano.com/arreglando-el-arranque-de-windows/)
With these commands I could set the hard drive partition as active.

list disk
select disk = X
list partition
select partition = Y
active
exit X

X is the disk number associated with your main hard drive. You check this number with the list disk command.
Y is the disk partition. Usually has the value 1.

Then, I could execute the previous commands successful (bootrec).

5) Change boot order.
The next time I restarted the PC I got this error: "bootmgr is missing".
The only avaliable option was "Press Ctrl+Alt+Supr" to reboot, and then back to the same message.
In this situation I was not able to boot from win7 install DVD neither. So I went to BIOS again and I changed the devices boot order by selecting DVD as first option. In this way, next time it will try to boot front win7 install DVD again.

6) Replace bootmgr (https://answers.microsoft.com/en-us/windows/forum/all/bootrec-error-element-not-found/cac41df1-0590-4ea3-b7cd-134256e84c8f)
Using win7 disk I put the following commands:

bcdboot C:\windows /l es-ES

One more reboot and success!!!!