Make NAS (Network Attached Storage) devices work in Vista

If you are like me and have a NAS device on your network that is not
compatible with Windows Vista, now you can tweak Windows Vista to make
it work again. You do not even have to wait for your device manufacturer
to release a new firmware any more! Just follow these steps below:

Click on the Start Button and key in secpol.msc in the search box and
hit Enter.
When the Local Security Policy editor has loaded, expand Local Policies
and select Security Options.
Scroll through the list and locate "Network Security: LAN Manager
authentication level." Right click on this setting and select Properties.
Change the setting to "Send LM & NTML - use NTLMv2 session security if
negotiated"
Hit OK and your NAS will work again.
Using theses instructions I was able to make my 1 TB Buffalo TeraStation
work with Windows Vista. Prior to changing the authentication level, I
could not access any secured shares on my NAS.

-- From 9/1/2006 by Steve Sinchak
http://www.tweakvista.com/article39001.aspx