>>>Hi,
>>>
>>>
>>>With SQL Server 2005 installed I install the SQL Server 2000.
>>>Now, when I try to access SQL Server 2005 I get this message where try to login.
>>>
>>>
>>>
>>>TITLE: Connect to Server
>>>------------------------------
>>>
>>>Cannot connect to DELL.
>>>
>>>------------------------------
>>>ADDITIONAL INFORMATION:
>>>
>>>An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) (Microsoft SQL Server, Error: 2)
>>>
>>>For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=2&LinkId=20476
>>>
>>>------------------------------
>>>BUTTONS:
>>>
>>>OK
>>>------------------------------
>>>
>>>
>>>
>>>
>>>
>>>>Yes, I've done so and have no had any problems.
>>>>
>>>>>Hi,
>>>>>
>>>>>
>>>>>Can I to install "SQL Server 2005" and "SQL Server 2000" in the same computer without problem ?
>>
>>Geraldo,
>>
>>SQL 2000 and SQL 2005 should have different instance names. I know that SQL 2005 will not let you install over 2000 with the same instance name. I don't know if SQL 2000 works the same. You may have both versions sharing the same instance name.
>
>
>Yes, with the same login and password the two versions works, but a Data Base that I have in 2005 version can't be opned. When I try to Atach in the new instance an error message is displayed.

Are you using Enterprise Manager to try to attach the database? I think that by default the Named Pipes protocol is disabled in SQL Server 2005. Try SQL Server Management Studio instead of Enterprise Manager. It uses the new SQL Native Client to connect to the database and it will automatically upgrade the mdf to SQL 2005 when you attach it.

If you want to continue to use EM to connect to SQL 2005, you will have to enable the Named Pipes protocol. Look in the new help files under network protocols for how to enable it.

But I suggest that you use SQL Server Management Studio to connect. It is Enterprise Manager and Query Analyzer all wrapped up into one tool. And it will also connect to your SQL 2000 database and perform all of the tasks that EM does - except for SQL 2000 database diagrams and DTS package editing.