Update to OS X Tiger 10.4.5 and suddenly lose the ability to access your shares from your Windows PCs. Don’t worry, you are not alone!

The fix is quite simple when you know it (and a pain in the ass if you don’t).

1) On your Windows PC, set the Domain (or Local) Security Policy setting “Network security: LAN manager authentication level” to “Send LM & NTLM - use NTLMv2 session security if negotiated” On Windows XP Professional on a stand-alone machine, this setting is in Start -> Run -> secpol.msc -> Security Settings -> Local Policies -> Security Options.

2) Run gpupdate.exe or restart your PC. This refreshes the group policy settings to take into account the change we just made in step one to the Security Policy.

3) On your Mac, open Terminal and type: <pre>sudo nano /etc/smb.conf</pre>

4) Under [global], make sure you have the following settings set: <pre>auth methods = guest opendirectory
passdb backend = opendirectorysam guest
client ntlvm2 auth = yes</pre>

5) Save the file by pressing the “Ctrl” and “O” keys at the same time. Close Terminal.

6) In System Preferences, Stop “Windows Sharing” in “Sharing”. Then Start it. This restarts Samba.

That’s it! Hopefully (!), you should now be able to access your shares!