Step 1: Boot into Windows 10
Make sure your laptop is powered on and Windows 10 is fully booted.
Step 2: Remove Ubuntu partition
1. Press Win + X and select "Disk Management" from the list.
2. Locate the Ubuntu partition (usually labeled as "ext4" or "Linux").
3. Right-click on the Ubuntu partition and choose "Delete Volume".
4. Confirm the deletion when prompted.
Step 3: Repair Windows bootloader
1. Insert your Windows 10 installation media (USB or DVD).
2. Restart your laptop and boot from the installation media.
3. Choose your language preferences and click "Next".
4. Select "Repair your computer" and then "Troubleshoot".
5. From the troubleshoot options, select "Command Prompt".
6. Run the following commands to fix the bootloader:
bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd
7. Restart your laptop.
After following these steps, the Ubuntu operating system will be removed from your laptop, and Windows 10 should boot normally. Please note that modifying disk partitions and bootloaders carries a certain risk, so it's recommended to back up your important data before proceeding.