Just after an upgrade from Ubuntu 10.10 to 11.04, Ubuntu freezes at startup on a dialog saying: "It seems that you do not have the hardware required to run Unity. Please choose Ubuntu Classic", etc.
So far, I've not been able to bring up any sort of UI, graphical or text, not even once.
The mouse doesn't work, nor does the keyboard. I can't click the "Close" button. I can't switch either to another console or UI. I tried ALT + Print Screen, R E and that didn't work either.
Rebooting leads me back to the same place. Right now I would be delighted if I could just get the system back to what it was pre-upgrade (which was just fine).
Does anyone have any idea what to do?
Nothing on the keyboard works. I'm still frozen at startup, with seemingly no way to intervene in the process. Neither the mouse nor the keyboard seems to work--the machine doesn't respond to any keyboard input--and there doesn't appear to be any point in the process that I can get to an alternate UI (i.e., another shell, or "Recovery Mode") to issue commands that could possibly re-assign the window manager from Unity back to what was there in 10.10. This my first experience with Ubuntu on a personal PC, and I'm not familiar with "booting into Recovery Mode". Also, this is not a machine I want to just wipe clean and start over with. We've been using it as my wife's primary home PC and she's got a lot of material on it she needs now and can't do without. I really want to get this fixed. The PC is an HP Pavillion a450y, which uses the ASUS P4SD-LA PES revision 0.01 motherboard. The video specs for this include "Integrated 3D graphics controller" and "In Springdale chipset". The boot sequence doesn't give me an opportunity to use "Recovery Mode": when I turn on the machine and get past the BIOs screen, it flashes and goes directly to the frozen dialog box. It does not present me with any intervening screen where I can choose an alternate boot destination (such as the "Recovery Mode"). ** So, is there some way to interrupt the boot sequence before it freezes? Is there another way to boot the system--say, off of a CD, for example--that will allow me to edit some of the config files mentioned above on the hard disk? **