Setup Dual booting system and Reset Computer

Here a list of concepts I learn as I went through this exercice:

UEFI:  "Both UEFI and BIOS are low-level software that starts when you boot your PC before booting your operating system, but UEFI is a more modern solution, supporting larger hard drives, faster boot times, more security features, and—conveniently—graphics and mouse cursors."  (definition from this website)

Dual booting: When the second system is installed, in my case Ubuntu, it install a boot loader which allows to pick between two OS when starting. Ubuntu uses GRUB. Normally the bootloader is installed in a different parition, in my case a FAT32 partition of around 32GB. 

GNU GRUB (or just GRUB): is a boot loader package that supports multiple operating systems on a computer. During boot-up, the user can select the operating system to run. GNU GRUB is based on an earlier multiboot package, GRUB (GRand Unified Bootloader). GRUB is most often used on Unix-like systems, including GNU, Linux and Solaris.

Boot configuration Data: To edit boot options in Windows, use BCDEdit (BCDEdit.exe)

Booting Partition: Grub is installed normally into it's own partition. If the partition is corrupted you can recover it with a Windows usb drive. There are several commands (bootrec /fixmbr, bootrec /fixboot, bootrec /ScanOs  , bootect /rebuildBcd)

If there issues with those commands you might have to format the partition.

Reset Windows Installation

Windows allows reset easily as long as a recovery partition is enabled. 

Windows Recovery Environment: Its commonly save in a hidden partition (1GB in my case) and it contains a winre.wim file. A windows recovery enviornment can be specified for the current windows installation with the following commands:

bcdedit /enum all: to check the the current configured recovery partition (if there is one)

reagentc /info

If there is no recovery environment configure and once we locate the wim file we can set the path like this:

reagentc /setreimage /path C:\windows\system32\recovery

Then we just run reagentc /enable to activate the it.