"When someone asks me about upgrading their computer for the most noticeable performance gain, I commonly tell them to install an SSD. The reason is that both your start-up and shut-down times will drastically decrease. Likewise, you will experience shorter transfer times and faster loading on any program installed on the drive. These are only some of the perks that you'll quickly gain by using an SSD, such as the Corsair Force GT. Having said that, the reduced power consumption in SSDs make them ideal for use in laptops and netbooks. This upgrade does, however, come at a cost."
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips