Just download the new v4.25 then exit BOINC from running. If you are running v4.19 now you will have to un-install that first then install v4.25 ...
If you are running v4.20 or higher now you can just install v4.25 right over them ... All your work should be saved and continue where you left off when you start up v4.25 after it is installed ...
Will downloading new BOINC version affect current work?
)
Just download the new v4.25 then exit BOINC from running. If you are running v4.19 now you will have to un-install that first then install v4.25 ...
If you are running v4.20 or higher now you can just install v4.25 right over them ... All your work should be saved and continue where you left off when you start up v4.25 after it is installed ...