Upgrading hard drive to a SSD

I would go with a SSHD hybrid drive Vs a SSD if you want need to replace your current HD. Seagate makes a nice one that way you gain the speed of the deep cache of the SSD but still have the storage space of a traditional HD. Here's the drive: Desktop 3.5" SSHD. I would stick with the 1TB drive.

While the dual drive option looks tempting the optical drive in this system is PATA which is way too slow for the SSD. Your systems HD SATA port is SATA II (3.0 Gb/s).

Going with a SSD is doable but will be limiting based on how big a unit you get. Given the age of the system you most likely don't want to spend too much here. Don't forget the SSD will be 2.5" so you'll need a adapter frame to hold it if you do go with the SSD.