The enhancer won't replace or rebuild what wasn't there. Last time I cautioned you to not expect that home video camera to provide the quality you'd find in a studio. This time the caution is to not put your trust in an enhancer. They serve a purpose, but a minor one. They exist to transform an existing image.
Many enhancers also claim to have the capability to reduce noise.
Noise is any unwanted signal. In video it exists primarily in the high frequencies. To reduce noise, those high frequencies are reduced. This also results in loss of image purity and quality. If the enhancer is used to improve image resolution, it does it by increasing those high ends.