SQL server 2005 SP4 error

I am trying to install sp4 on our server, but when I am Installing it is showing below error.

The product instance sqlname does not have prerequisite update 5000 installed. Update 5292 is dependent on prerequisite update 5000. Exit setup and refer to the Knowledge Base article to find the prerequisite patch. Install the prerequisite and rerun the installation.

current version:

Microsoft SQL Server 2005 - 9.00.4035.00 (X64) 
    Nov 24 2008 16:17:31 
    Copyright (c) 1988-2005 Microsoft Corporation
    Enterprise Edition (64-bit) on Windows NT 6.1 (Build 7601: Service Pack 1)