Just ran into a strange problem with Task Scheduler under Windows Server 2003. We had a bunch of tasks that suddenly stopped running, and the Last Result status codes were 0x1 and 0x80. These tasks were running as NT AUTHORITYSYSTEM. When I ran it via the command line, it ran fine. When I changed the user to my own local user, it ran fine. The log only showed “The task completed with an exit code of (1).”
Googling was of no use.
Seeming at random, a co-worker suggested that I peek at our memory usage. It was at 50% over the physical memory limit, and there were dozens of processes running that were stuck. After running a taskkill /F /IM, everything was back to normal!