This question already has an answer here:
- What should I do when Ubuntu freezes? 39 answers
I am a new user. I recently installed Ubuntu 11.10 as a dual boot on a fairly standard Dell Dimension, 768 RAM, Intel 2 GHz chip. The first few times I ran it it was a bit slow, with a lot of flickering of the mouse cursor, but then it seemed to settle down. Today, the screen has frozen. I was running Firefox, gedit, and Terminal. Neither the mouse nor the keyboard seem to work, although I am not familiar with the control sequences I might use in Ubuntu, such as Ctrl Alt Del (is there something like task manager on Windows?). Could anyone please advise me on such control sequences, and if they fail, how I can find out what is causing the problem?