below a link to a executable (it restarts the ESET service while ESET is running) and script provided by ESET which will allow you to fix you update issues without having to reboot the servers. I have also included the KB article which has the steps on what to do if you can reboot the server.
hxxp://download.eset.com/special/eset_update_fix.exe
@ECHO OFF
set “updFix=\\server_name_here\eset\eset_update_fix.exe”
%updFix%
del "C:\Program Files\ESET\ESET File Security\em009_32.dat"
del "C:\Program Files\ESET\ESET File Security\em009_64.dat"
echo %time%
timeout 5 > NUL
echo %time%
%updFix%
Exit
hxxp://support.eset.com/alert5553/
A number of customers have run the above and it has rectified their update issues. Please let me know if you require any further information.