Thanks a lot. These seem to be useful starting points. But my main goal is to do this on a constant basis (ie. not having to look my process up in the table manually every time rather do it automatically from the script) and having a look at the Win32::Process module it seems to me that if I open the process that way I won't have handles to the STDIN and STDOUT of the process, while if I open it through Open2 (as I do currently) there is not a Win32::Process object on which I can perform $ProcessObj->SetPriorityClass($class). There seems to be no method for creating a Win32::Process object from a pid.