Upon booting, my beautiful black MacBook looks normal, and the cursor moves normally. But clicking has no effect. This is true with the touchpad, and also when I use a wireless mouse. Sometimes the screen then freezes. Keyboard short cuts and the arrow keys seem to work, but that doesn't (I think) let me do several of the troubleshooting suggestion s in the owner's manual. I have tried rebooting (with and without installation disk inserted) holding down option, or C, or D, or option-command-P-R. I am willing to clean install, but have to click to do that. The MacBook is 13 months old. Software up to date. Hardware or software? Any suggestions? For a few hours before this problem prevented me from using the laptop, I was getting erratic graphics, e.g. lag time between moving the pointer and its actually moving, trying to select one file but getting another when I clicked. I managed to get to Disk Utility once (not sure how), and its default hardware test showed no problem (I could not click the box to do the longer test). I cannot get Disk Utility any more. Upon booting, I can sometimes get to the HD directory, but selecting Disk Utility (or anything else) and then hitting "enter" just prepares the file name to be renamed. Many thanks for thinking about this.