Step 1: First download the ubuntu from this link :

Step 2: Download the UNetbootin from this link:

Step 3: Right click of your computer icon and click manage.After that it will take you Computer Management directory and then select Disk Management and right click on your disk drive.And then select shrink volume and create a partition arond 20gb or more depending on how much space you want to give to the linux installation.After that click on shrink and after the partition is created .

Step 4:Now go to download folder and launch UNetbootin.Select DiskImage and browse for the Linux OS ISO image from the download folder(in my case ubuntu).On "Type" select HDD insteated of USB.On "Drive" select C:\ and then click Ok and wait until it creates the bootable setup.Now click on Exit and restart your windows pc.

Step 5: On the next restart it will show you a boot menu option select UNetbootin

That's it!