I got some plants from my friend that were covered in powdery mildow. It is spreading to the other plants in my room that had no powerdery mildow what can i do?
Removing the plants won't help much now since it's already spread to your other plants. You can spray the plants with various water mixtures including things like baking soda, non-fat milk, etc. or you can do a sulphur burn. Do a search and you'll find tons of information on powdery mildew. It sucks ass but it is controllable.