Recently I received a debugging request for a customer having problems running large executables. On their systems, they could run most EXEs without any problems, but they had two programs that were over 1.8 GB which, when run, would display the following error: If they tried to run them in a command prompt, they received the message “Access is denied.” Both attempts were made with an administrator account and in neither case were the processes created. Through testing, they found that the programs worked if they were scheduled to run as System and also worked when run in safe mode as an administrator. When the case was brought to my attention, it was noted that when the failing executables were run, the following appeared in process monitor logs: The engineer did not see this when one of the problematic EXEs was run (successfully) on his test machine. The customer provided a VM image of their system which we set up in HyperV with a named pipe kernel debugger. I then started kernel debugging to find the cause of the INVALID PARAMETER error, hoping that resolving it would fix the issue. Read more: Ntdebugging Blog