Duel Boot (Ubuntu + window)

You have to be sure about following points, before installing dual boot:

1. Make sure you have backup of current data.
2. Ensure that your computer meets the minimum system requirements for both Ubuntu and Windows.
3. Before proceeding, it is a good idea to create recovery drive or system image. It helps to restore windows in case of lose.
4. download ubuntu setup from https://ubuntu.com/download/desktop, and make a bootable Usb using https://rufus.ie/en/.
5. Shrink the windows partition by searching "Disk Management" option from windows search.
6. Point to focus: Configuration settings used be in UEFI not legacy else you may have issues.
7. Reinstall or shutdown the system and then start and press "F12,F5 etc.." to enter in boot menu & follow the installation steps.
8. Once the Ubuntu installation is complete, restart your computer. 9.If you want to change the default operating system that loads by default, you can usually do so through the boot menu or the BIOS/UEFI settings.