The answer to that is "it depends." Obviously if it is a false positive from Avira and you end up deleting a file that your OS or an application needs, those will cease to work properly. Also depending on the OS, when something is deleted it isn't exactly deleted. Delete will just remove the addressing of where something is on a drive and until that location is overwritten by something else can be retrieved by those that know how.
"A government big enough to give you everything you need, is a government big enough to take away everything that you have...." -- Thomas Jefferson
"The U. S. Constitution doesn't guarantee happiness, only the pursuit of it. You have to catch up with it yourself." -- Benjamin Franklin
"I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them." -- Thomas Jefferson