What you ask for is not possible. This question has been asked by many over the years. I have several installations for the same computers that I would have liked to merge as well. I have learned to transfer the directory from the old installation to the new to preserve the device ID. I think there is only one file that truly needs to be moved.

Cheers

No, BOINC doesn't use the computer name. I have many devices in my device history with the exact same device name, yet they are not the same device.

It might be the host_cpid (cross project id) within the file C:\ProgramData\BOINC\client_state.xml. I have just moved or saved the entire folder when re-installing or upgrading OS. I have always been crunching on a Windows OS; there may be complications if switching between Windows and Linux.

Cheers

Just for your information, I recently tried this (moving device profile from Windows to Linux) and it worked like a charm. So at least it is worth trying if you really do not want a new device in your list.

Since the science apps are obviously different, first you'd need to do is drain the tasks from the Windows install, then stop the client and make a backup. Then I'd imagine 1 or more control files need to be ported to the BOINC install on Linux, like e.g. account_www.worldcommunitygrid.org.xml , in the right place, with the right ownerships and property settings. That Linux client must of course not be (never?) be started / to be stopped. I'd image the client_state.xml could come across too. Maybe in the Linux connectoid, set same LAN IP, BUT, it violates a lot such as WTH were previous results processed by if they ever need to reconcile problems. Picture the Windows machine did 1 or more Beta26, techs run analysis on results and go Vhat?