Modifying the menu is possible, but a bit involved, since Windows has no proper facility for doing so and it involves turning off all the automatically-added items, then adding them back manually in the places you want them:
An easier (but less precise) solution is sometimes to turn off the unwanted context menu items in the programs adding them, or block the programs from being added if they don't have an option to turn them off. Things like the WinRAR items can also be moved into a sub-menu to tidy things up a bit.
Personally, I use the method in the linked post, but it does require some digging around in the registry etc. to get full control over everything in the menu.