upgrade avamar client from 7.5.0 to 18.2 on windows server

Hi All;

I have question about upgrading avamar client from 7.5.0 to 18.2 , when I upgrade it, it pops up the windows 

1) close the applications and attempt to restart them

or

2) Do not close application. A reboot will be required

I don't want to reboot server, which option do I need to choose ? Thank you.