I finally got it working, so I thought I would post what I did here in case it is of assistance to someone else.Just to clarify, QNX is _not_ a Linux distribution. QNX is a POSIX-compliant (meaning it looks just like UNIX), realtime operating system. It is commonly used for process control, industrial automation, medical systems etc. I am using a really old version that is impractical to upgrade due to a huge porting effort for many different applications, including Samba.I am using Samba backwards to the way most people think of it. QNX added to the old version of Samba with a utility called SMBfsys, which allows mounting Windows shared folders and printers so they can be accessed by applications on the QNX system. So a QNX executable can modify files on drive C: and print to Windows printers and so on. Samba can still be used in the normal sense to allow Windows users to access files on the QNX system, but that is not how I am using it (and at this point, it only works with Windows XP and earlier, but I am not troubleshooting it).I finally solved the problem by using Wireshark to analyze the packets. It is pretty good at displaying the message content. It turned out that the old version of Samba was sending a Lan Manager encrypted password, but Windows 7 didn't have a copy to compare that with, so it produced a permission denied error.Windows Home Premium does NOT include the group policy manager, so everything must be done with registry modifications. Good luck to typical home users that might ever try to connect a Windows 95 computer to Windows 7 !The following registry settings were needed:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa"LmCompatibilityLevel"=dword:1 -allow older Lan manager style messages"NoLmHash"=dword:0 -store the older, less secure Lan Manager encrypted passwordHKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Netlogon\Parameters"AllowNT4Crypto"=dword:1 -allow less secure encrypted passwords (intermediate keys must be created)HKLM\System\CurrentControlSet\Services\LanmanServer\Parameters"RequireSecuritySignature"=dword:0 -don't require new message signaturesThis value may have already existed, I don't remember