Connecting to an SQL Server using a workgroup

I am trying to I am trying to connect to an SQL Server using a vb.net program. It works if
I put it on the SQL Server computer, but will not connect over my local
network that is set up as a workgroup. I get the following message:
Login failed for user 'DELL4100\Guest'

DELL4100 is the computer name where the sql server is on.

The connection string is:
Data Source=dell4100;Database=dbname;User ID=dbn;Password=password;
I have also tried Integrated Security=SSPI; instead of the User ID &
Password.

I do not know why it is using Guest instead of the User ID that I specified.
So, I created a Login name in the SQL Server called Guest with no password.
I also activated the Guest account in XP for both machines. Still the same
message.

I created accounts for dbn on both computers and gave them the same
password. I logged in under dsn and ran the program, but I still get the
same error.

I turned off the Windows firewall on both computers. I can share files and
printers between computers, just not access the SQL Server.

Can anyone help?

Thanks

Tim
using a vb.net program. It works if
I put it on the SQL Server computer, but will not connect over my local
network that is set up as a workgroup. I get the following message:
Login failed for user 'DELL4100\Guest'

DELL4100 is the computer name where the sql server is on.

The connection string is:
Data Source=dell4100;Database=dbname;User ID=dbn; Password=password;
I have also tried Integrated Security=SSPI; instead of the User ID &
Password.

I do not know why it is using Guest instead of the User ID that I specified.
So, I created a Login name in the SQL Server called Guest with no password.
I also activated the Guest account in XP for both machines. Still the same
message.

I created accounts for dbn on both computers and gave them the same
password. I logged in under dsn and ran the program, but I still get the
same error.

I turned off the Windows firewall on both computers. I can share files and
printers between computers, just not access the SQL Server.

Can anyone help?

Thanks

TimSomehow my message got mangled. I was editing the message and the time limit expired.

I wanted to add that the SQL Server is on an XP pro sp2 machine and that tcp/ip and Names Pipes are enabled and that it is listening on port 1433.|||I have the same issue, is there already an solution ?|||Try to create DSN to the server on your computer. If it doesn't work then it is not your code is a problem.
It is my only guess your SQL drivers are corrupt.|||I have the same question too. I just had to reinstall SQL server on a lab server that crashed, used to have a 'domain' windows 2003 setup but for some reason was set up as a peer-to-peer workgroup. Old way was to create sqlserver logins like: Workstation1\JoeDoe... now it says that is not a legal login, and I can;t 'find' anything but the server name? (I can otherwise access shared files between machines, etc.) . Is there some sql server issue with peer-to-peer networks?