|Following on from the above replies, do not use MSCONFIG to manage your startup items. MSCONFIG is intended only for troubleshooting purposes.|
To disable or re-enable any startup item use Ccleaner: http://www.filehippo.com/download_c...
Ccleaner shows all your startup items in one complete list and is therefore by far the best and easiest utility for managing them.
There is no way to tell you which items can be disabled as everyone's PC has different software installed. Only you can decide, but if you "Google" each startup item to see what it does, that will help you make a decision.