1. I tried different ways to remove it, I firstly launched BootCamp once again and when it was busy removing the partition, it stopped saying an error message. I tried multiple times, didn't work. Secondly, I tried to use disk utility like it said on Apple website. I went to disk utility, erased, and formatted it to the type that it said on the Apple Website. Here is the instructions =
- Start up your Mac in OS X.
- Open Disk Utility, located in the Other folder in Launchpad.
- Select the Windows disk, click Erase, choose the Mac OS Extended (Journaled) format, then click the Erase button.
However, when I followed these instructions, instead of the disk named Windows, it was named BootCamp. I still followed the instructions, but they did not work.
2. Here are the results :

