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If you are referring to Boot Camp Assistant, you can't delete it easily because it's a system application. Also, it doesn't take a lot of space, so there isn't any reason to delete it.
If you have installed Windows in Boot Camp and you want to remove it, there isn't any disadvantage. Just open Boot Camp Assistant (in /Applications/Utilities) and follow the steps to delete Windows. The space that was taken by Windows will be added to Mac OS X
No, but you must delete it correctly (using Boot Camp) or your day will get worse