Hi Patil
Kindly follow the steps
1. Stop the SAP instance.
2. Take the full backup of DB & SAP instance folder
3. Download the latest version of MS SQL 2005 and start install the service pack.
4. Check the service pack version which already mention in the SAP Notes 62988
5. Restart the system, check the SAP instance
6. Refer the SAP KBA for download the service pack
1733195 - Microsoft SQL Server version and download list
BR
SS