My guess is your hard drive is meeting its end life. Change it into SSD, and you will feel frustrated for wasting your life not getting SSD earlier. Upon changin into SSD, I can predict your laptop will need less than 15 sec to start up. My netbook with crappy 1core 2 thread intel atom 1,2GHz only need 10 sec to finish start up after i put my old 60Gb SSD into it.
If your HDD is really the problem, get an SSD. Its worth it. You might not need to upgrade your laptop until the end of its life. 480Gb/500Gb SSD currently around $130 in states.
Oh I forgot to mention, upon using SSD, your battery will hold more as SSD uses much less electricity than HDD. In my netbook, it double the battery life, from 1 hour (yeah its crap) into 2 hour (still crap, but its for my nephew school use).