I currently use windows 7 home premium. I want to try ubuntu without changing my original OS windows 7. When I get accustomed to ubuntu, then I am gonna migrate to ubuntu. In the mean time, while booting from ubuntu live CD, will my original OS be deleted?
The "Try Ubuntu" option is different from the "Install Ubuntu" option.
When you use the "Try Ubuntu" option runs the Ubuntu OS from the live cd itself and does not install it to your hard drive.
If you decide to install Ubuntu, then you have to make sure to do a side-by-side installation, otherwise it could accidentally wipe windows, but that is different than the "Try Ubuntu" option.