Normal file fragmentation scatters the pieces of a file all over your hard disk. This invariably also affects the files that load at boot time. You can defragment the files that load at system startup to enable faster loading.
Navigate to:
HLM\ SOFTWARE\ Microsoft\ Dfrg\ BootOptimizeFunction
A setting called Enable under this key needs to be set to Y (for Yes). This setting defragments the boot files, and it might relocate startup files into contiguous clusters on the volume, reducing the movement of the disk head when reading the volume.
