Update Identity name in SharePoint Config DB for 'The specified user or domain group was not found ' error

Hi All,

When i navigate to Manage Service Application page in central admin i am getting "The specified user or domain group was not found" error.

Recently our network people changed my system name. After that i updated SharePoint server name and sql server names with new system name.

I am able access Central admin. but i am not able access manage service application page.

For this i followed with this url - http://crazzycoding.blogspot.in/2011/07/specified-user-or-domain-group-was-not.html

after running the SQL command : i found the old username for Identity in User Profile Service Application XML file.

<sFld type="String" name="m_SerializedAcl">&lt;acl&gt;&lt;ace identityName="i:0#.w|nt authority\network service" displayName="nt authority\network service" sid="" allowRights="18446744073709551615" denyRights="0" /&gt;&lt;ace identityName="i:0#.w|olduser\admin" displayName="0#.w|olduser\admin" sid="" allowRights="18446744073709551615" denyRights="0" /&gt;&lt;/acl&gt;</sFld>

In above how can i update with new user.

or should i disconnect farm and run the SharePoint configuration wizard to build new config db ?

i hope you all get my point and help me soon.

MD.Liakath ali