HDD's are fastest at the start of the first partition because its at the edge of the disc (inside the HDD) and they get slower the closer the read head gets to the center of the disc. this is simply because the outside edge of the disc is moving faster then the inside edge and the read head can access more information faster when its nearer to the outer edge of the disc.
in general HDD's performance is normally all over the place so that is not really a concern.
if windows is taking a long time to load try.
making sure all windows updates are installed
all drivers are up to date
use Ccleaner to clean up the registry and disable unneeded start programs.
delete any and all facebook games, things like weatherbug and other useless applications that just #$#$ on your pc.
make sure you have at least 4 gigs of ram, preferably 8-16gb
buy an SSD, once you use one you never go back.
also turn windows firewall on, its not the best but its better then nothing and if its not interfering with the software you use you might as well leave it on.
if turning windows firewall OFF sped up your PC then i would definitely check to make sure your networking drivers (most likely they come bundled with your chipset drivers if its onboard) are up to date and install spybot S&D 2 and spybot anti beacon to root out anything fishy.
windows firewall should take almost none of your systems resources when its on under normal conditions.