Hi, My setup is. (setq inferior-lisp-program "C:/Program Files/Steel Bank Common Lisp/1.0/sbcl.exe") (add-to-list 'load-path "C:/Program Files/Emacs/site-lisp/slime-2.0") (require 'slime) (slime-setup) When I execute M-x slime I get the error message "Spawning child process: invalid argument". Experimenting a bit, I found that: (file-exists-p inferior-lisp-program) returns t (set-variable 'explicit-shell-file-name inferior-lisp-program) + M-x shell will get me a SBCL "shell". After moving SBCL to c:\sbcl and changing my config to (setq inferior-lisp-program "C:/sbcl/sbcl.exe") I tried M-x slime again and everything worked fine! I've been looking through the slime source (both 2.0 and the latest snapshot) and the split-string calls in slime-read-interactive-arg sure looks suspicious. Is this a known issue? /A