Are you having problem in accessing CD or DVD drive of your system? Delete the upper and lower filter of registry to eliminate this problem from your system. If you leave the problem untreated then it might cause serious problems in your system. This can be done manually but it involves lot of risk with it. If you don't acquire technical knowledge then you can experience lot of problem in your system. Possibilities of system crash are also there.Therefore it would be safe if to use a Registry repair tool for this purpose. This tool will diagnose the entire registry of your system and remove Upper and lower filter registry value. Hence the problem get resolved from your system and the CD and DVD drive become accessible. For more information log on to: http://www.upperlowerfilterserrorfix.com