Hmm are you wearing socks?
You should be grounding yourself, especially when on carpet. Otherwise, you risk the chance of zapping your motherboard without realising it and, well, frying it. It is a very rare thing, but I noticed you are on carpet. I stand on carpet, but I go barefoot with flip flops when I work on my PC, and I use an antistatic wrist band connected to my other PC's steel to ground myself and prevent this from happening.
A wrist band is not necessary, touching a grounded piece of metal every so often works too. Read this http://www.tomshardware.com/forum/322660-30-ground-yourself