OK, well most of the items on the left are removed by right clicking on them and choosing "remove from the list" or "unpin from start menu".
Keep in mind the programs below the dim line on the left are placed there automatically. Windows will add programs that you commonly use, however it has been known to favor itself and MS programs you may have never used. If you want to stop this, right click on an empty spot of the taskbar and click properties. Then click the "Start Menu" Tab, then click "Customize". Down at the bottom, you'll see "Number of recent programs to display". This is the number of programs MS will list automatically that it believes you use the most. You can put any number here, usually between 0 -10.
Hope that Helps.
Added:
Recheck "store & display recently opened programs in the start menu" and then adjust the number in customize at the bottom.
Also, Check out this in the tutorial section, once there click on the "S":
http://www.sevenforums.com/tutorials/?filter[2]=Taskbar%20Start%20Menu