Hi, I'm having a strange thing happen to me. When I'm using my computer, every now and then (or about every 30-60 mins) a blank cmd.exe window randomly flashes up in the top left corner of my screen for a fraction of a second. It's so fast that the only reason I could read it is cos I took a video of my screen and waited for it to happen again. This has only been happening since yesterday. I tried to restore my computer to a previous point because it was also acting slower than usual and making more crackling noises than usual; my computer is acting OK now but the cmd window is still flashing. Another thing that happened to me since yesterday was my firewall said it blocked something called netsession_win.exe and I asked it unblock it before I restored my computer and it asked me again after that so I told it to block it. I don't know whether or not this is relevant. I am using Windows XP, and I put all my details in my profile. Please help me, I'm worried something bad is happening .