How to Remove Windows.old folder Easily

When you upgrade your Windows OS from Windows 7 to Windows 8 or form Windows 7 32 bit version to 64 bit version without formatting the previous Windows drive, the system keeps your previous(old) Windows program and related files in windows.old folder.

If your recently installed OS is working fine as expected, it is better to delete your Windows.old folder permanently which is eating your 9 to