A jobmate told me his home system was slow to start and crawling along at startup. So I adviced he disable all programs except the antivirus at msconfig > startup. Next day he told me this at first worked right, but after another system start, he said the system got unstable with error dialog boxes showing up. My friend says he enabled all those programs back in msconfig > startup, but no hope.
I've learned a lesson: no matter how insignificant a change to a system, do a system backup, but...isn't it surprising that simply disabling a few programs not to start with windows can create such trouble?.
Agreed there are often many items running in the Sys tray that are unnecessary, especially on branded laptops etc. I usually run Spybot in Advanced mode, it has a Startup Tool which lists all processes and gives advice on many of them as to whether they are necessary or not, you can either disable them safely or delete the ones you know are useless. (You have to 'slide' the information pane on the right of the window to see the advice...) Hope your pal doesn't have to re-install...