Do certain ones slow down applications and system resources slow down apps from starting and browsers to open slowly? If they do, Which suite is the better to install and prevent this from happening? I use KIS 2019. thx
It depends how much you value your data as many of the applications that slow program start up are performing software checks to ensure as best as possible, the software is not trying to sneak anything underhand into its load up routine.
If KIS is slowing down your computer I would switch to Windows Firewall Control 5.3.1.0 + Kaspersky Virus Removal Tool. A properly configured Firefox will do a lot for your Internet security too.