10 - 15 minutes to make ONE brush

Okay. So. I've been trying to make brushes, but it takes forever just to make one. I can make the brush but when I want to turn it into an actual brush, it freezes my whole PSP9 for 10 - 15 minutes and it affects my whole computer by freezing it aswell. I have tried tons of things. I've even reinstalled it. Is there anything I could do to actually fix this? Please and thanks.