Once we download the latest released patches from microsoft and after installing all the patches, without restarting, I can see all the patches are available in control panel. Do I really need to restart the servers? will the installed patches get applied without restarting. what happens if we don't restart the servers at all.

yes, you need to restart the server. While they seems to be appear in control panel, some systems files cannot be replaced in installation process, because they are used by the system. The only way to replace these files is to restart computer. System will disconnect all programs from the file and update it.http://www.sysadmins.lv

If you're prompted to restart after applying one or more patches, then yes, you need to restart.Paul Adare CTO IdentIT Inc. ILM MVP