Ricoh

Hi How often does SCCM refreshes its All System collection with computers from AD. So if a new computer is added in the AD, how long will it take for SCCM to recognize that. Another question i have is, Alot of clients have CLient NO and Approve NO in the status, meaning that i am unable to deploy anything to them. The thing is that most of them have the client installed already. I used a toolbox called SCCM collection commander to run something called Refresh DataDiscoveryReccord (DDR). It helped with i think around 90% of all the clients i were strugling with, but some are still stucked with the status Client NO Approved NO. Is there a way i can get those out of that status?