First of all:
Does sa have permissions on 'DB'?

Second (obvious one): Is SQL Server up and running when you this?

Third:
Try accessing the server by it's IP:
String connString="server=(local); database=DB; uid=sa; password=;";
or
String connString="server=127.0.0.1; database=DB; uid=sa; password=;";
or any other IP.

D'Mzz!
RoverM

If when your are browsing your sql server, the name of the instance (under the SQL server group) is Instance don't change it to (Local) or anything. Try this one instead:

connString="server=Instance; initial catalog=DB; uid=sa; pwd=;"

PS
If it doesn't work that way either.
1) R u sure your SQL server is running?
2) The sa passward is blank?

Hope i was helpfull,

Orbital.

How do I add a user to the db? 'sa' is reserved, but I do not see it in the list. When I try to add a different user, it says "login already exists."

SQL Server Enterprise Manager, if I expand Databases\myDB, click on 'Users', there is only 1 item: "dbo".
If I double-click "dbo", a 'databse user property dialog' shows. In Permit in databse role, only 'public' is checked. If I click "permission", myTable has all select, insert, etc checked (except for EXEC).

If I right-click 'dbo' ->New Databse User, I cannot add 'sa', it is 'reserved.' I cannot add my Windows account, it says 'already exists.'

What do I do?

Samliam,

I think what you want is to drill into Security -> Logins instead of Database -> Users.

Try this and you should see the Windows account that you you're trying to add already exists.  Right-Click and then set the access permissions as necessary.

I would still recommend that instead of doing this you change your access validation to SQL Server and connect as you were trying in your original post.  Windows validation can be more difficult to troubleshoot so I'd get an SA connection working first and then move to Windows validation if that's where you want to be.

Hope that helps...

I had the same problem.
My SQL server 2000 database running on WIN- NT and server name in 'NTSERVER'.
SQL server name also 'NTSERVER'.

I installed .NET in my machine (Win 2000) and create connection string in ASP.NET to NTSERVER.

I receievd the same error message 'SQL Server does not exist or access denied', when I try to connect with IP address instead of server name on Data source - It's connected.

I need alternat solution other than IP address.

Pl, provide solution ...

you want to use server name instead of ip address, be sure that you've added an alias for the said server on the client utility or host file and they are not in conflict with one another

I have the same problem!!!

i tested the user credential with enterprise manager and all seems right

but by code also if i use de sa login i receive the same message:
SQL Server does not exist or access denied
this is my connection string:
Connection Timeout=20;Server=192.168.254.50;Database=DBNAME;Persist Security Info=False;Trusted_Connection=true;User ID=sa;Password=XXXX;

try:

Connection Timeout=20;Server='192.168.254.50';Database=DBNAME;Persist Security Info=False;User ID='sa';Password='XXXX';

i resolved it
yes was "Trusted_Connection=true"