1. To prevent programs from ‘attaching themselves’ (your words) to the start up process, you will have to look at the Options/Preferences of those programs, or for malware.
2. However, if you mean “How do I reduce the number of programs that run at start up“, Quick Startup is the best free program and it’s easier than Microsoft’s msconfig.
It runs all operating systems, get it here
http://www.glarysoft.com/qs.html?tag=download Click on (highlight) an entry, then in the left pane choose Disable or Delete. If you are unsure about an entry and want to know more about it before disabling or deleting it, highlight it and then click ‘More information’ at the bottom of the screen.
If you want to add programs to the start up process, be careful if you‘re running a 64-bit system. It’s best to add new programs to the Start Up folders as there are two sets of ‘Run’ keys in the 64-bit versions.