When you run SFC, you are prompted for credentials on the i386 share, even though you are logged onto the domain with administrator credentials?
If the i386 share is hosted on a Windows NT 4.0 computer, the server does not know how to authenticate computer accounts.
To resolve this issue, edit the registry on the Windows NT 4.0 server that is hosting the i386 share:
1. Use Regedt32 to navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters
2. On the Edit menu, Add Value name RestrictNullSessAccess, a REG_DWORD data type, and set the data value to 0.
3. Add a NullSessionShares entry for the i386 share.
4. Stop and restart the Server service and any dependent services.