If your Start Menu is very tall, and refuses to become smaller
If you customized your Start Menu, increasing the number of recent programs to display and the number of recent items in jump lists, it may have become very tall, which is rather ugly.
There is no registry key you can edit to change the height of the Start Menu. Its height is configured automatically by Windows according to the number of recent items that need to be displayed. The strange thing with the Start Menu, is that its height does not depend only to the “Recent Programs” number, but also to the “Recent Jump Lists Items”, although the later are not visible immediately when you open the Start Menu.
Therefore, it is not enough to decrease the number of recent programs, you need also to decrease the number of recent items displayed in Jump Lists, in order to bring the Start Menu to the size that you prefer. As for myself, I have 8 recent programs displayed, and 12 recent items in the jump lists.
To change these numbers, right click on the Windows globe and select “Properties”, then go to the “Start Menu” tab > Customize and you will find these numbers at the bottom of the “Customize Start Menu” tab.