I contacted my host provider. They helped me with the database restoring. Then, i had new error:

Login failed for user '****'. Server Error in '/' Application.
------------------------------
*Login failed for user '****'.* *Description: *An unhandled exception
occurred during the execution of the current web request. Please review the
stack trace for more information about the error and where it originated in
the code.

*Exception Details: *System.Data.SqlClient.SqlException: Login failed for
user '****'.

*Source Error:*

An unhandled exception was generated during the execution of the current
web request. Information regarding the origin and location of the exception
can be identified using the exception stack trace below.
*Stack Trace:*

[SqlException (0x80131904): Login failed for user '****'.]
System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection
owningObject) +428
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection
owningConnection) +65
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection
outerConnection, DbConnectionFactory connectionFactory) +117
System.Data.SqlClient.SqlConnection.Open() +122
Microsoft.ApplicationBlocks.Data.SqlHelperParameterCache.DiscoverSpParameterSet(SqlConnection
connection, String spName, Boolean includeReturnValueParameter,
Object[] parameterValues) +233
Microsoft.ApplicationBlocks.Data.SqlHelperParameterCache.GetSpParameterSetInternal(SqlConnection
connection, String spName, Boolean includeReturnValueParameter) +343
Microsoft.ApplicationBlocks.Data.SqlHelperParameterCache.GetSpParameterSet(String
connectionString, String spName, Boolean includeReturnValueParameter)
+175
Microsoft.ApplicationBlocks.Data.SqlHelperParameterCache.GetSpParameterSet(String
connectionString, String spName) +45
Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(String
connectionString, String spName, Object[] parameterValues) +207
DotNetNuke.Data.SqlDataProvider.GetPortalAliasByPortalID(Int32 PortalID) +92
DotNetNuke.Entities.Portals.PortalAliasController.GetPortalAliasByPortalID(Int32
PortalID) +43
DotNetNuke.Entities.Portals.PortalSettings.GetPortalAliasLookup() +75
DotNetNuke.Entities.Portals.PortalSettings.GetPortalAliasInfo(String
PortalAlias) +16
DotNetNuke.HttpModules.UrlRewriteModule.RewriteUrl(HttpApplication app) +3384
DotNetNuke.HttpModules.UrlRewriteModule.OnBeginRequest(Object s,
EventArgs e) +1018
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
+68
System.Web.HttpApplication.ExecuteStep(IExecutionStep step,
Boolean& completedSynchronously) +75

------------------------------

At first , i thought the problem was about the user roles. So, i added all roles for the user. But the error is still on.

So, the "movie" continue :)

I checked many times the web.config. It seems all proper there. Its something from the SQL Server, but i am not sure what is it. I sended email again at the hosting provider for help, and i am waiting now for answer.

Here is the last:

======================
Server Error in '/' Application.
--------------------------------------------------------------------------------

Compilation Error
Description: An error occurred during the compilation of a resource required
to service this request. Please review the following specific error details
and modify your source code appropriately.

Compiler Error Message: BC30560: 'DataProvider' is ambiguous in the
namespace 'DotNetNuke.Modules.HTML'.

Source Error:

Line 40:
Line 41: ' singleton reference to the instantiated object
Line 42: Private Shared objProvider As DataProvider = Nothing
Line 43:
Line 44: ' constructor
Source File: C:\Domains\domain\wwwroot\App_Code\HTML\DataProvider.vb
Line: 42