JSI Tip 5681. The Windows XP and Windows .NET defrag utility optimizes the boot files

If you do a clean install of the subject operating systems, the built-in defrag utility will optimize the placement of the boot files.

If you upgraded your O/S, you might want to verify that the Enable Value Name, a REG_SZ data type, has a data value of  Y, at the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizeFunction.

NOTE: If you change the Enable data value, you must shutdown and restart your computer for the change to become effective.