If you haven't already, adding a SSD will be one of the biggest and best (in terms of value) improvement you can do for your computer.

Starting up your computer, and launching applications will benefit greatly from a SSD. The other potential bottleneck would be your CPU and RAM, but they are more than capable enough to handle your needs. RAM would probably be the next thing to upgrade if possible. But from what it sounds like, with a laptop, this might be quite difficult.

Worst comes to worst you can always put the SSD towards your new pc. Adding onto that, SSDs are already very cheap and prices are only dropping further.