How can I increase the size of the pinned jump list in Windows 7?

1. Right click on the Windows orb/start button and click Properties.
2. Click the Start Menu tab (if not already selected).
3. Click Customize...
   
4. Set Number of recent programs to display and Number of recent items to display in Jump Lists to to something like 20.
   

This also makes your start menu super tall, allows you to add more pinned programs to your start menu and more pinned programs to your pinned programs jump lists.

You don't need the jumplist launcher to do that.

I was wishing that when the limit was reached it would become a scrollable jump list like they do when you click all programs on the start menu. That would be ideal! Does the jumplist launcher do that?

Browse to the following key in the registry editor:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ApplicationDestinations\MaxEntries

Change the decimal value of Max entries to whatever you like (the default is 17).

I was just doing this in Windows 8.1 and thought I'd add an answer to show the differences in that OS:

1. Right Click on the taskbar and go into properties.

2. Go to the Jump Lists tab.

3. Change the number of recent items to display in Jump Lists to a suitable number, the maximum is 60:

   

4. Click OK

The recent items and pinned items share the space, so the number you set is a total across both types of item. If you set it too high, then it will go off the top of your screen - with a 1200px vertical, I can fit about 45 items in a full-height jump list.