An SSD drive is the single most efficient way to improve the speed of your machine, and the motherboard has SATA connector, so you're good to go. Connect, install system, that's it.
(The hardware specifications:http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00619307&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=1847627
But before you start spending money, you should check out prices of current notebook models. There are some pretty cheap ones that will still be faster than your old dinosaur after having changed everything except the case.