So in advance I'll just say I am a total linux newbie, so be kind. I just downloaded Ubuntu 11.10 and this is my first experience with Linux. I enjoy it so far and actually enjoy it except for when my computer freezes. This has been quite often so far. I've done a little research and it seems my problem is with the GPU. When it does freeze I can move the cursor but cannot click on anything. I also cannot run Alt+F2 xkill. So my only previous experience has been with Windows and I would normally solve an issue like this with Ctrl+Alt+Delete and just shut down the offending program. I do not know how to do this in Ubuntu and not even sure this would even work. Please help me if you can, how do I deal with a freeze without having to resort to a hard shutdown, I cannot seem to run the computer over one hour without experiencing this issue. I tried accessing my GRUB menu on startup but I can't even seem to do that. Also the only real program I have been running whenever this happens seems to be Firefox. Thank you, appreciate any help. After running lspci | grep VGA command prompt: 00:12.0 VGA compatible controller: nVidia Corporation C67 [GeForce 7150M / nForce 630M] (rev a2)*****