Connecting from in C# application to SQL Server 2000

[Zikica Jevtic]

I have installed Microsoft Visaual Studio .NET Architect.

I have big problem when I tray to connect to SQL Server 2000 data
table using SqlDataAdapter:

1)
I use SqlDataAdapter wizard to connect to one table on SQL Server
2000.
I make new connection and test it. That works.
I use Query Builder to make SELECT SQL statement (just simple like
select * ...). After that wizard ask me for username/password. I type
same username/password like when i tested connection in a same wizard
and i get error:
"The connection could not be opened because of the following error:
The specified module could not be found.."

2) I use OleDbDataAdapter instead SqlDataAdapter over wizard in the
same way. Everithing looks OK (in same order like in 1)). On the end i
have data in OleDbDataAdapter Data Prewiev. But, when i try to fill
data set in my code with: OleDbDataAdapter.Fill(dataset) function i
get new error: "An unhandled exception of type
"System.Data.OleDb.OleDbException" ocured in system.data.dll"

3) Also when i create new dataset and try to drag and drop some table
from my SQL Server from Server Explorer I get same error message like
in 1).

I reinstalled .NET but nothing wasn't helpfull.
What is problem ?

I am totaly blocked !

Please tell me if you now solution !

Thanks !
Zikica