tl;dr don't use this, have a look at cmd start /affinity instead

runcpu is a program that can be used for launching Windows processes with a pre-set affinity and working directory.

Running the program goes more or less like this :

runcpu -d "D:\working_directory" -a 3 -- D:\foo.exe -arg1="foo bar" -arg2="bar foo"

Such an invocation will run D:\foo.exe with the affinity set to 0x3 (so, the process will be allowed to run on CPU 0 and CPU 1), and the working directory set to D:\working_directory. Parameters -arg1="foo bar" -arg2="bar foo" are passed verbatim into D:\foo.exe.

I originally wrote this tool because I wanted to spawn a number of virtual machines on my Windows XP computer, with each of them bound tightly to only one physical CPU. For some reason, I couldn't get it to work with standard Windows utilities, so I decided to try it on my own.

I doubt whether this is of any use to anyone at the moment, since I'm sure doing something like that is possible with PowerShell, which is much more suitable to such tasks.