Can't connect after change the security setting

Hi, Experts! I very new to SQL server. I made a stupid movement by mistakenl
y
change the security of property of local(windows NT) from log in using this
account to system account. After the machine restarted, i can't no longer
start up SQL server. When I click local (window NT) in enterprise manager it
says "a connection could not be established to local. Reason, SQL serer
doesn't exist or access denied". I think it is the change of security that
the access was denied. How should I resolve this problem' Thanks so much.Thats weird, did the SQLServer service start up ? Look in the Service
manager. The service account can be switched in here. if you changed
the authentication method you can set it back via the registry entry as
mentioned in here:
---
http://support.microsoft.com/defaul...b;EN-US;q285097
---
INF: How to Change the Default Login Authentication Mode to SQL While
Installing SQL Server 2000 Desktop Engine by Using Windows Installer
---
<snip>
Another way to change the security mode after installation is to stop
SQL Server and set the appropriate registry key for your installation:
Default instance:
HKLM\Software\Microsoft\MSSqlserver\MSSq
lServer\LoginMode
Named instance:
HKLM\Software\Microsoft\Microsoft SQL Server\Instance
Name\MSSQLServer\LoginMode
to 2 for mixed-mode or 1 for integrated. (Integrated is the default
setup for the SQL Server 2000 Data Engine.)
</snip>
-URL---
HTH, Jens Suessmeyer.|||Jens,
Thank you so very much for your reply. I changed the registry loginmode from
2 to 1 and it did not work; I tried to change from 1 to 0, it did not work
either. In the service, I was not able to start up MSSQLSERVER. I got this
message "MSSQL SERVER service on local computer started and then stopped.
Some services stop automatically if they have no work to do ...".
Thanks.
"Jens" wrote:

> Thats weird, did the SQLServer service start up ? Look in the Service
> manager. The service account can be switched in here. if you changed
> the authentication method you can set it back via the registry entry as
> mentioned in here:
> ---
> http://support.microsoft.com/defaul...b;EN-US;q285097
> ---
> INF: How to Change the Default Login Authentication Mode to SQL While
> Installing SQL Server 2000 Desktop Engine by Using Windows Installer
> ---
> <snip>
> Another way to change the security mode after installation is to stop
> SQL Server and set the appropriate registry key for your installation:
>
> Default instance:
> HKLM\Software\Microsoft\MSSqlserver\MSSq
lServer\LoginMode
>
> Named instance:
> HKLM\Software\Microsoft\Microsoft SQL Server\Instance
> Name\MSSQLServer\LoginMode
>
> to 2 for mixed-mode or 1 for integrated. (Integrated is the default
> setup for the SQL Server 2000 Data Engine.)
> </snip>
>
> -URL---
>
> HTH, Jens Suessmeyer.
>|||Lokk in the event log to see why it failed, did you try to change the
service accoutn back to the original one in the service manager ?
Some error occured and you have to know which one, this information is
presented in the event log.
Jens Suessmeyer.|||Thank you Jens. You saved me. I was panic about it. It is the evaluation
period expired. We have license now. How can I update the license without
losing the data? If not doable it is ok too. Thanks. whew...
"Jens" wrote:

> Lokk in the event log to see why it failed, did you try to change the
> service accoutn back to the original one in the service manager ?
> Some error occured and you have to know which one, this information is
> presented in the event log.
> Jens Suessmeyer.
>|||http://support.microsoft.com/defaul...kb;en-us;281574
HTH, Jens Suessmeyer.|||Thank you so very much Jens. You are very helpful!!
"jsuessmeyer@.web.de" wrote:

> http://support.microsoft.com/defaul...kb;en-us;281574
> HTH, Jens Suessmeyer.
>