i have white dots on my screen how can i fix it
Is it a DLP system? If so, buy a new one. The millions of little mirrors that spin at thousands of rotations per minute are failing. It's a big issue with Mitsubishi.
If it's not a DLP, it's probably skin flakes from a dog, use windex and wipe off the screen, left to right.
If you don't have a dog, perhaps you have a daughter (teen) that is sun tanning and the lotion has embedded on the screen. In this case, use vinegar ammonia windex and wipe RIGHT to LEFT.
If you don't have a teenage daughter, perhaps there are dust particles on your glasses, in this case, use the ammonia based windex and clean your glasses from UP to DOWN motions.