Samba escapes filenames which cannot be used under Windows, such as COM1, allowing files with these names to be accessed from a Windows machine. However according to the list from Microsoft[1], there are some reserved names which Samba does not escape and thus those files cannot be accessed from Windows via Samba. Samba escapes COM[1-3], but not COM[4-9]. It escapes LPT[1-3] but not LPT[4-9]. [1] http://msdn.microsoft.com/en-us/library/aa365247.aspx