First of all, the classic client didn't work. It was just showing a blank window after loading. Then I tried launching the OpenGL... same problem. I saw Sir Rambo post and Thomy's replies. I uninstalled the old one and installed the new client, and I launched the OpenGL on the new Desktop client..it worked fine, until I hit the minimize button and it stopped working(not responding...15 seconds of waiting and then gone). I thought it was something wrong with my computer(eh...s**t happens), so I relaunched, and again same problem. Then , after another 2 more attempts, I gave up. Well, my account is still on (45 mins and going)...

Try restarting your computer. A crashed client instance could still be running. Regarding the minimize issue, can you type ::opengl info and show me that? You probably need to update your graphic drivers to get rid off that issue or use the classic client.