The laptop won't turn on, only after the BIOs

Hi, I'm Robinson, and I’m happy to help you today.

When you install Ubuntu the Windows bootloader is replaced by the Grub(Linux bootloader), by deleting the Ubuntu you also delete the Grub making your computer won't able to load Windows. You will need to create a bootable flash drive with the Windows installation to be able to repair the boot files.

Step 1: Create a bootable flash drive using the Media Creation tool and boot from it.
https://www.microsoft.com/en-us/software-downlo...

Step 2:

1-On installation, screen click on "Repair your pc" on the left bottom
2-Click on "Troubleshoot"
3-Then the Advanced Options page will appear.
4-Click on "Command Prompt".
5-Run these commands:
chkdsk c: /f /r (and press Enter)
sfc /scannow (and press Enter)
diskpart (and press Enter)
sel disk 0 (and press Enter)
list vol (and press Enter)

6-Verify that the EFI partition (EPS) is using the FAT32 file system and assign a drive letter to it that is not already in use:
sel vol <number of volume> (and press Enter)
assign letter=Z: (and press Enter)
exit (and press Enter)

7-In order to repair the boot record:
cd /d Z:\EFI\Microsoft\Boot\ (and press Enter)
bootrec /FixBoot (and press Enter)
ren BCD BCD.old (and press Enter)
bcdboot c:\Windows /l en-us /s <boot letter>: All (and press Enter)
(Note: The <boot letter> is replaced with the letter of the drive that you are booting from. (For example, C:\, D:\)

8-When finished close the command prompt then click to return to the first screen
9-Click to continue to normal boot

I will try that. This will not delete my data on Windows?

At the moment I have found a solution, let me see what you think about it. When I enter BIOS/Boot settings I have UEFI Boot Order, OS Boot Manager goes first and then USB Diskette on Key. I moved it so that USB goes first, then OS Boot Manager and now it's normal for me, it turns on immediately. Can I leave it at that?

If you are able to boot on Windows after changing the boot order without a USB flash drive connected you don't need to make any changes, but if you are able to boot on Windows only with a USB flash drive connected you will need to execute the procedure above to repair the boot files.