I am experiencing the same issue. Windows Client version 2.4.8 on Windows 7 64bit PC with 4 core processor. urbackupcclientbackend.exe service is using 25% CPU usage or ~100% of one core continuously. I’ve exited the tray application and the usage continues, I need to stop the service for the CPU usage to stop. When I restart the service, it will soon resume to consuming 25% or 100% of one of my cores. I’ve also tried reducing the backup window on the client to see if that would have any impact on reduced usage outside the window but it did not seem to help. Anyone observe this usage and is it normal / expected?