1. Bioinformatics

There are two different answers here, depending on what you want from your startup: good experience, or massive success. The best minimal age to start a startup.

Hi, You don't have to have any StartUp programs - most are there for convenience. One antivirus program is good to keep if shown in StartUp.

Bioinformatics

You did not indicate your version of Windows so here are method for Windows 7 which also will work in Vista and with a little modification in Windows 8. You can use these to control what programs startup. Many that install themselves into StartUp do not really need to be there. Such as Acrobat Reader (Adobe), WinAmp Agent, and many others which load pieces of themselves to start faster (not an issue on today's machines) and to be sure they can control the files they support (to be sure you continue to use only them). Those are only common examples and not meant as a slam on those fine programs. How to troubleshoot a problem by performing a clean boot in Windows Vista or Windows 7 How to Change, Add, or Remove Startup Programs in Windows 7 Autoruns - Free - See what programs are configured to startup automatically when your system boots and you login. Autoruns also shows you the full list of Registry and file locations where applications can configure auto-start settings.

Performance and Maintenance Tips Hope this helps.