Hi, the function slime-file-name-merge-source-root from slime.el does not work on windows, because it adds a slash in front of the device in a pathname. That causes emacs to call ange-ftp to a nonexistant machine. The attached patch solves the problem by checking whether the original path started with s slash and only then inserts a slash again in front of the buffer root. Hope this is useful Carsten C:\slime\slime>diff -u slime.el.orig slime.el --- slime.el.orig 2007-09-27 09:48:45.062107200 +0200 +++ slime.el 2007-09-27 10:03:52.929040700 +0200 @@ -4444,15 +4444,17 @@ (push target-dir target-suffix-dirs) (let* ((target-suffix (concat-dirs target-suffix-dirs)) ; PUSH reversed for us! (buffer-root (concat-dirs (reverse (nthcdr pos buffer-dirs*))))) - (return (concat (file-name-as-directory "/") - buffer-root - target-suffix - (file-name-nondirectory target-filename)))))))))) + (return (concat (if (equal (substring buffer-filename 0 1) "/") + "/" + nil) + buffer-root + target-suffix + (file-name-nondirectory target-filename)))))))))) (defun slime-highlight-differences-in-dirname (base-dirname contrast-dirname) "Returns a copy of BASE-DIRNAME where all differences between BASE-DIRNAME and CONTRAST-DIRNAME are propertized with a -highlighting face." qhighlighting face." (setq base-dirname (file-name-as-directory base-dirname)) (setq contrast-dirname (file-name-as-directory contrast-dirname)) (flet ((insert-dir (dirname)