Start-up items

I have software PowerSuite Wincare 2010 by Spotmau. It allows me to disable many applications at start-up. So I’ve got that sorted out without any problems.

But in MSCONFIG there are many items checked in WIN.INI which are recognizable applications. Is it OK to uncheck the items that I recognize? Are there any items in WIN.INI or Startup that are essential and must not be unchecked?

Running the various procedures in PowerSuite Wincare reduced the boot-up time in one computer (which is top heavy with applications) from 10 minutes to 3.5 minutes. I would like to improve on this without mucking up the system.