After upgrading from XP to Visa I cannot access my network shares. I have a Toshiba SG30 and a Linksys EFG250 - both are Network storage devices. The username/password box pops up and I enter correct usernames and passwords, but each and every time Windows claims the logon is incorrect. However, if I try and connect to other XP boxes on my network, and I'm asked for username/password - it works fine ... I do not have this problem on my XP machines. What's wrong here ????

Does the NAS device support NFS? If so add NFS support to windows and try to connect from the command line with the "mount" command.

I found the solution - in the secpol.msc console, Network Security: LAN Manager authentication was set on the wrong setting. I changed it to "Send LM and NTLM responses" and all is OK now .... Don't know if the "incorrect" setting was by design or not, but I spend a better part of an evening banging my head against the wall.

LM or lan Manager is an older technology that is being phased out, expect that this was set correctly according to that