What version of Windows do you have? Either way, the simplest way is to open Task Manager (Ctrl+Shift+Esc), go to the Startup tab, and just disable the programs you don't need at startup. Nothing bad will happen there - the apps will stay in place, they just won't load with the system.
If you don't see the Startup tab, you've got an older version of Windows - then you can go through system settings or directly to the Startup folder. But in modern versions, Task Manager is the way to do it and takes about half a minute.