Solved: task manager - start items

I have lots of items listed in start up , all enabled. What is the impact of disabling some of these items as there are programs there that I don't need at startup but do use during the course of the day i.e adobe reader ; my canon printer etc. Are there any specific things in the list that I should NOT disable - I don't know what many of them do and don't wish to muck things up for the sake of some housekeeping
Thanks guys/gals
Mikey