RunFirst is a command line utility that lets you start an application on the first processor of a multi-processor system or on an hyper-threaded single processor system.

What this utility does is the same as what you can do using the Task Manager -> Set Affinity command.

RunFirst is useful to start an application that crashes when running on a multi processor system. The runfirst.exe command can be inserted in a shortcut so that when you start an application the process affinity is automatically set to run on a single processor.


Windows NT 4 (at least SP6), 2000, XP , 2003, Vista, 2008, 2008 R2, 7, 8 (32-Bit & 64-Bit).