If you want to speed up access to your favourite applications then you could spend some time carefully organising the relevant shortcuts on your desktop. But you'll quickly run into a problem, especially if others share your PC - they can easily rearrange the shortcuts however they like, and there's not a lot you can do about it. Unless, perhaps, you install DeskLock.
Once launched the program places an icon in your system tray. Make sure the desktop is arranged as you'd like, then right-click the DeskLock icon, select Enable, and that's it. You can double-click on shortcuts, files or folder icons as before, but it's no longer possible to move them from one place to another.
Some of the techniques employed here are a little extreme. Changing the sort order of the desktop will mess up your icon arrangement, for instance, so by default DeskLock disables the desktop right-click option altogether. That seems like a step too far for us (although you can at least restore the right-click with a tweak in the program Settings dialog). Still, if you're setting up a PC that will be accessed by many users, or people with little Windows experience, then you'll need a way to protect your system configuration, and DeskLock could be a small but simple part of that.