Noise removal tools are a band-aid for rescuing recordings over which you have no control. They always affect the wanted sound, and not usually in a beneficial way. If you are getting machine noise because of recording with an internal mic in a laptop that makes mechanical noises (hard drive or cooling fans usually) you should find a way of recording so you don't get that noise in the first place. Then you don't have to mess your sound up with noise removal tools. You'll have a far better recording for several other reasons too, such as (almost certainly) a better mic, and the freedom to position that mic where it will get the best sound.