I am using a mid-2012 MBP 13in with no retina display, running OS X 10.8.3. Everything was fine until I was watching a video clip on Facebook. Everything just froze, except the mouse pointer can still move, but I can't do anything else. So I was forced to long press the power button to shut the machine down. After that, the whole system was ridiculously slow.
I can boot into my own account, but starting/running/closing any program takes ages. Also, when I tried to mount a
.dmg. I was given a error message like "No suitable file system." I know I can just re-install the by booting into the recovery partition, but I'll take that as my last resort.
Here are more screenshots of the Activity Monitor: