Right-click on the Start button itself and choose Open All Users.
Double-click on the Programs folder. You will see all of the files and folders on the Start menu.
Then in the menu at the top, click on File/New/Folder, then give the folder a name like "Unused Stuff".
Then start dragging and dropping things into that folder (or cut and paste them) that you don't want to see on the Start menu.
When you close that window and click Start/All Programs, you'll see the new folder you created as an entry on the Start menu with all of the stuff you put in it.
If you really think you don't need the stuff, first go through Add/Remove Programs in the Control Panel and remove the stuff you don't need. Dell (and many other manufacturers) put a lot of junk on the systems.