Disk Fragmentation

Ran a search and found many with same problem.... my disk becomes fragmented at an alarming rate compared to previous versions of Windows. 

I use Norton Systemworks (could schedule Windows Defrag) and my concern is that I am scheduling defrag at least twice a week (I am getting 15% + fragmented in less than a week) and even right after defrag, it is 2-4% fragmented.  I have been told that closing all programs (I do this using End-It-All) would help.  It does, dramatically.  However, I have to do this manually each time and would prefer to defrag in the middle of the night rather than waiting 45 minutes during the day.  Any suggestion?  Thanks,  Dave