Why can't I uninstall programs from my vista ultimate laptop?

I have admin rights and I can uninstall some programs but not others. Many programs don't show the uninstall option when selected. Please help!

Why can't I uninstall programs from my vista ultimate laptop?computers

due to the fact that some of the programs are used by other programs you cant uninstall them, try clicking on them for information they should take you to a website for information. also you can go into C drive and take them out from there but I dont recomend doing this if you have no idea about computers.

Why can't I uninstall programs from my vista ultimate laptop?hijack this

Is there a particular program. Norton requires downloading the Norton removal tool.