How To Unlock Bootloader, Flash Twrp, Root, Flash Rom Xiaomi Redmi Note 7

1. Disable driver signature enforcement in Windows
If your computer doesn’t recognize Xiaomi drivers then please disable driver signature enforcement. How to do this please read here: http://en.miui.com/thread-237673-1-1.html

2. Install ADB and Fastboot tools with drivers on Windows
How to do this please read here: Click Here

3. Enable "OEM unlocking" and "USB debugging" in your device
a. Enable Developer Options in: Settings/About Phone/MIUI version. Click on MIUI version seven times

b. Now go to: Settings/Additional Settings/Developer Options and check "OEM unlocking" and "USB debugging"

4. Check if your bootloader is locked
a. After successful installation of "ADB and Fastboot" enter the fastboot mode by holding together "Volume Down + Power" and connect your device to your computer via USB cable (best would be the original cable).

b. Go to the folder where you have put the "ADB and Fastboot" and open a command window inside that folder. To do that hold together "Shift + Right Click" on any empty white space inside the folder and then select "Open PowerShell Window Here" or "Open Command Window Here"

c. Enter the terminal command in command line: >>fastboot devices<<
If you don't see your device it means that the drivers weren't installed properly or the device wasn't connected properly. If this happens please reinstall your drivers from Point A. 2. or try these drivers here:
http://xiaomiadvices.com/download-xiaomi-usb-drivers/

d. If you see your device then enter the terminal command in command line: >>fastboot oem device-info<<
If your bootloader is locked, you'll get the following status (or something similar):

…………………………………………………………………….
(bootloader) Device tampered: false
(bootloader) Device unlocked: false
(bootloader) Device critical unlocked: false
(bootloader) Charger screen enabled: false
(bootloader) Display panel:
OKAY [ 0.058s]
finished. total time: 0.063s
………………………………………………………………………

If your bootloader is unlocked, you'll get following status (or something similar):

…………………………………………………………………….
(bootloader) Device tampered: false
(bootloader) Device unlocked: true
(bootloader) Device critical unlocked: true
(bootloader) Charger screen enabled: false
(bootloader) Display panel:
OKAY [ 0.053s]
finished. total time: 0.055s
………………………………………………………………………

5. Request Permission from Xiaomi to Unlock the Bootloader
a. Create a Mi Account: https://global.account.xiaomi.com/pass/register

b. Sign to Xiaomi and apply for unlocking http://en.miui.com/unlock
You have to give a reason for requesting to unlock the bootloader. Something like:
"I purchased my Redmi Note 7 from the vendor xxx and they have installed a fake/custom rom. I want to install an original rom from Xiaomi. So please approve my request to unlock the bootloader."

c. Wait for permission. If your request is approved then you should receive a message with following content:
"You've been granted the permission to unlock your device (Mi Account xxxx). Donload Mi Unlock Tool At http://en.miui.com/unlock"

6. Connect your Mi Account to your Device 
Go to: Settings/Additional Settings/Developer Options/Mi Unlock status and check "Add account and device"

B: Unlock the Bootloader

• Unlocking the bootloader will erase all your data! So please back up your data before you unlock the bootloader!
• You must enable "OEM unlocking" and "USB debugging" as per point A. 3.
• You must connect your Mi Account with your device as per point A. 6.
• Download Mi Unlock Tool here: http://en.miui.com/unlock 
• Enter the fastboot mode by holding together "Volume Down + Power" and connect your device to your computer via USB cable (best would be the original cable)
• Start the Mi Unlock Tool
• Enter your eMail and your password of your Mi Account
• Connect you device to your computer and start the unlock procedure
• Follow the unlock tool instructions until the unlock procedure is finished
• Reboot your device

If you get the message, that the unlocking can be done after 72h or 360h or 720h etc., then you have to wait for that time to pass.

C: Install the TWRP Recovery
Not yet available. To be updated soon.

D. Root Your Smartphone
Not yet available. To be updated soon.

E. Install A Custom Firmware
Not yet available. To be updated soon.
If my guide helped you please click "thanks" and enjoy your phone.