Are bitcoin generators legal please? I found quite a few on You tube google and yahoo search engines and I am trying to find out if they are legal or illegal to use.
The legal question is overriden by a technical one: Are bitcoin generators possible? And this must be answered with a resounding "No".
Every single bitcoin ever in existance was "generated" with the start of the blockchain - they only have to be found ("mined"). Bitcoin miners are quite simple machines (or programs running on general purpose computers), that use immense calculation power to find them. They are not only legal, but the standard way to put bitcoin into the cycle.
Legality aside, Bitcoin mining with a computer will not get you very far (see this Bitcoin stack exchange answer). That answer is a couple years old so it is even less possible now than it was then. Mining via a bitcoin generator is at least a waste and at worst a scam (or malware). Most mining is now done be dedicated hardware designed specifically for that purpose. CPU/GPU mining of bitcoin is not profitable.