Win 10 client not found after wake-on-lan in Professional Posted Friday at 05:28 AM · Report reply robr, You don't say what version of the Retrospect Windows "backup server" you are running, nor do you say whether this particular Windows "client" is being backed up with a Backup script or a Proactive script. In addition, you don't supply any information about what makes the other Windows "client" different from this Windows "client". This 2012 post says, for Retrospect Windows 7.7, "If the computer is already asleep, then retrospect will not run. There are 2 places to enable 'Wake on Lan' in retrospect, but I have found that it does not actually work (and yes, WOL works on my machine from other apps and is enabled in the bios)." Presumably that is why you are waking your "clients" with a Python script. Moreover, in spite of the fact that the Retrospect Mac Sources category has a checkbox under Client ->Options for enabling Wake-on-LAN, Retrospect Tech Support in 2016 verified my report that it wasn't working for Retrospect Mac 12 (equivalent to Retrospect Windows 10). However the cumulative Retrospect Windows Release Notes say, for 15.1.0, "Windows Client: Fixed Wake-On-Lan (WOL) for upgraded Windows client (#7358)". I suggest that you Remove that particular "client" machine's Retrospect Client from the "backup server", uninstall and re-install its Client program, and then re-Add the "client on the "backup server" (pages 277-293 in the Retrospect Windows 16 User's Guide)—after which you will have to re-Add it in each script that backs it up and drag its name into the appropriate sequential position (page 178 in the UG) . However it may be sufficient to do what this recent post in another thread says, which is that the Remove and re-Add etc. in the "backup server wasn't needed—only a clean Client delete and re-install.