Time to remove from crap from my media center computer

I was starting to find that my media center machine (Lenovo S12) is getting sluggish is performance regardless of whether I am watching media through the network or from an external USB harddisk. After looking into the issue, I found out that I have 2 machine sessions running (one from Windows remote desktop, and one by directly using the machine). But at the same time I also found that there are tons of stuff installed on that machine which I never use. So I think it's time for me to start reinstalling every single crap and only left those that are essential for media playback.