Are Ahmadis, Qadianis and Barelvis Muslim?

Answer

Ahmedis and Qadianis are not Muslims. They are the followers of Gulam Ahmed of Qadian who was an imposter who claimed to be a nabi. Salaat behind them is obviously not valid. Barelvis, although people of Bid'ah, are Muslims. Endeavour not to perform Salaat behind them. But in a situation where a Barelvi happens to be the imaam, the Salaat will be valid.