If you get a pop-up message when you go to my Start button that reads "There is not enough room to show all the items you have added to the Start menu. To display them, please choose smaller menu icons, choose a smaller number of items, or unpin some items" and have very few items pinned to the Start menu, you can disable this warning.
This message has confused many people. It seems to say that you've pinned too many items to the Start menu, but that's not the only possibility. The left-hand side of the Start menu holds two special collections of icons. Above the line are those you've pinned to the Start menu, and below are those that Microsoft Windows thinks are your most-used apps. If the total number in both groups is too large to display, one or more of the most-used apps won't show up, and you'll get the warning.
Right-click on the Taskbar and select 'Properties' then click on the 'Start Menu' tab and click on the 'Customize' button. In the middle, there's a control labeled 'Number of programs on Start menu'. Click on the Start button, count the menu items below the line, and set this value to match. Click 'OK' and 'OK'again, and the warning won't bother you again.