Following are the steps to resolved this issue....
A. Configure SharePoint Central Administration App Pool
1. Go to IIS Manager (inetmgr.exe)
3. In Properties > Click on Identity Tab > Select Predefined as Network Service. > Ok
4. Start Central Admin Site.
B. Configure Windows SharePoint Services 3 Search Service
1. Go to Services (Start > Control Panel >Administrative Tools > Services)
3. In Logon Tab Select Log on as: This Account .
4. Type a name as " NT AUTHORITY\LocalService " . No need to provide passwords keep it blank.
5.Click On OK and Restart the Service.
C. Configure Central Admin Site
1. Open Central Admin Site > Application Managment > (Search) Manage search service
2. In " Query and Index Servers " section click on " Microsoft Search Server Indexing and Query ".