To be honest I can not recall the last time I did loose rice in a microwave, but I have microwaved those packets of rice one can buy. (Loads of calories !) I suspect what you need to do is to put the rice in a bowl with water, cover, and then zap it with microwaves for a bit. Try reading the microwavable packets of rice in the supermarket for ideas on how long it'll probably need, and be prepared to give it a while longer if it doesn't seem fully done when you check on it.