You are prompted to insert a Windows XP SP2 CD when you try to run the System File Checker tool on a Windows XP SP2-based computer.

Resolution :

Method 1: Insert a Windows XP CD that has SP2 integrated

For more information about how to integrate software updates into Windows installation source files, click the following article number to view the article in the Microsoft Knowledge Base: 828930

Method 2: Modify the registry to point to the Windows XP SP2 Setup files

Start >> Run >> regedit
HKEY_LOCAL_MACHINE >> SOFTWARE >> Microsoft >> Windows >> CurrentVersion >> Setup
In the right pane, right-click ServicePackSourcePath >> Modify >> type %windir%\ServicePackFiles >> OK