The Exchange Information Store automatically redirects all restore operations to the Recovery Storage Group (if a Recovery Storage Group exists on the server). When a Recovery Storage Group is created on a server, Exchange checks to see if the database that is selected for the restore operation is present in the Recovery Storage Group. If it is present, the database files are restored to the Recovery Storage Group. If it is not present, the restore operation stops. Event messages that are similar to the following may appear in the application event log:
Event ID 1
Event Type: Error
Event Source: MSExchangeIS
Event Category: Exchange Backup Restore
Event ID: 9635
Computer: EXCHANGE
Description: Failed to find a database to restore to from the Microsoft Active Directory. Storage Group specified on the backup media is [GUID]. Database specified on backup media is [Database Name] (EXCHANGE), error is 0xc7fe1f42.
Event ID 2
Event Type: Error
Event Source: ESE BACKUP
Event Category: Callback
Event ID: 904
Computer: EXCHANGE
Description: Information Store (4000) Callback function call ErrESECBRestoreGetDestination ended with error 0xC7FE1F42 Database not found.
If you delete the Recovery Storage Group, the information store reverts to typical restore behavior. That is, restore operations are not automatically redirected to the Recovery Storage Group.
If you do not want to restore data to the Recovery Storage Group and you do not want to delete the Recovery Storage Group, create the Recovery SG Override value in the following registry key, and then set the value to 1:
HKEY_LOCAL_MACHINE \System \CurrentControlSet \Services \MSExchangeIS \ParametersSystem
When you create this value, the information store ignores the Recovery Storage Group during a restore operation. Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it
To create and configure the Recovery SG Override registry value: Important: Make sure that you delete the Recovery SG Override registry value when you no longer require it.
1) Click Start
2) Click Run
3) type regedit and click OK
4) Locate and then click the following registry key:
HKEY_LOCAL_MACHINE \System \CurrentControlSet \Services \MSExchangeIS \ParametersSystem
5) On the Edit menu, point to New, and then click DWORD Value
6) Type Recovery SG Override and clcik OK
7) On the Edit menu, click Modify
8.) In the Value data box type 1 and click OK
9) Quit Registry Editor
Important Make sure that you delete the Recovery SG Override registry value when you no longer require it.
Furthr details about recovery storage groups and advice can be found here