Prior to Service Pack 3, the Single Instance Store Groveler would grovel the entire volume, not just the SIS Common Store.
The behavior since SP3, and in Windows Server 2003 Standard Edition, is to grovel the path identified in the Directory Value Name, a REG_SZ data type, at HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tftpd\Parameters.
If you wish to revert to the earlier behavior:
1. Use the Registry Editor to navigate to:
2. The GrovelAllPaths Value Name, a REG_SZ data type, can alter the behavior. If the data value is 0, or if the GrovelAllPaths Value Name is missing, only the defined path is groveled. If the data value is 1, all paths on all volumes configured for SIS will be groveled.
NOTE: Starting with SP3, SIS reparse information in the 4 KB SIS link file is no longer deleted by the SIS filter driver when the SIS common store file cannot be found.