Not sure if this will help - but it was the answer to my problem and had to share.
I have just started using Windows 7 and could not access the NAS that I purchased last week. I was unfamiliar with SAMBA servers etc and was having trouble connecting through Windows 7 - getting "invalid logon username or password" message. No problems accessing through the browser. Googled the problem and changes to the authentication in the registry were recommended, but didn't work for me.
I had previously noticed when accessing the NAS that my drive was "not formatted". I knew it was. However, SAMBA servers, or certainly the one I have only accept FAT32 file systems. I formatted the drive using the NAS formatting utility. Going down the menu list within the NAS (through the browser), I noticed that all the information under the headings SMB Server and FTP Server, which was previously garbled, or indicated connection error, was now legible and USERNAMES had been allocated ie "GUEST" for the SMB and "anonymous" for the FTP Server. The PASSWORDS were blank or --------.
Previously I had been trying to use the admin/ admin username/ password that came with the instructions for accessing via the browser. This time I tried "GUEST" with no password and.........BINGO....I was in.
SUMMARY - 1) ensure NAS is formatted through the onboard utility and 2) use the username/ password under the SMB Server menu inside the NAS.
I hope this helps someone - the first time I've used a forum, so please excuse any naivity of forum useage.