No, only one copy CCleaner is running when this happens. I know this, because I click on the CPU column and can see that the program by itself is using up almost all of my resources. before I realized what a hog this program was, I was restarting everything. Now, if it happens (and it won't because I have disabled cleaning Firefox) i can wait it out for about four or five minutes when the cleaning is done and I am given control back by my computer. I don't know much about coding, but I would think that reports that CCleaner can open two or more copies of itself or that for any reason it needs over 90% of the computer's resources is a coding problem, not a user problem.