I am starting a long, memory and CPU-intensive run. I know how to change the process priority manually from the task manager.
Is there a way that I can run it at low priority from a
.bat file, since that is how I start it?
Start it with the Start /low command and parameter, e g Start /low c:\foo.exe.
If you want to start a program with spaces in path and with arguments, you need to specify a title as well: