Fixing the secure channel
If you suspect there may be a problem with the secure channel try this
PS> Test-ComputerSecureChannel -Repair -Verbose
VERBOSE: Performing operation "Test-ComputerSecureChannel" on Target "Win7Test".
VERBOSE: The secure channel between the local machine and the domain Manticore.org was successfully repaired.
The other thing you may want to try is resetting the password
PS> Reset-ComputerMachinePassword -Verbose
VERBOSE: Performing operation "Reset-ComputerMachinePassword" on Target "Win7Test".
use –verbose otherwise you won’t get any feedback as to progress