I need help fixing isass exe invalid parameter was passed to a service or funtion. I am unable to even get into the system to boot in a safe mode? I see this is not a new issue but I've not found an answer. I also see there is programs that will clean this problem up but if I can't get to the system how can I download the programs?
I wouldn't use any programs besides your Windows disk to clean up an OS. Insert your Windows disk, boot from it, and do a repair installation. Sounds like it somehow got corrupted, and the disk will replace it with the original.