usoclient.exe looks to be the new windows update mechanism file. I've been doing some digging trying to understand updates in Windows 10 and I tracked down the use of this file. If you open up command prompt and type usoclient.exe StarttInstall and keep the Windows Update settings window up at same time, it'll attempt to install a failed update. There are several different commands for the usoclient.exe in the files that contain settings for Windows Update under C:\Windows\System32\Tasks\Microsoft\Windows\UpdateOrchestrator