I had this issue with my last computer and now with my current one: On startup, multiple command prompt windows flash open before closing. I did not have this issue on the new computer for the first few weeks of owning it. The issue started immediately after playing Matchmaking in Counter Strike: Global Offensive. I had been playing CS:GO on ESEA for the weeks that preceeded going back to matchmaking. I believe matchmaking provides a backdoor for hackers to get into a person's computer. What can I do to clean my pc, other than wiping everything and starting over?