I have 3 HDDs and on /dev/sda1, I have Ubuntu 12.04 installed and also the bootloader is on the same disk.
After GRUB when I select Ubuntu 12.04 to boot up it freezes just after the GRUB screen and before the login screen. Here is an image attached 

![enter image description here](https://lh4.googleusercontent.com/-ewtkZqjSm_Y/UBOsUxc24jI/AAAAAAAAA5M/zh_NDqKpE4o/s1095/IMG_20120728_142516.jpg)

This is how this problem started.

I have Ubuntu 12.04 and I installed cinnamon, it was working fine, until I updated the Cinnamon. Cinnamon's new update had some problems and it used to freeze a lot while I was working on my computer. 

So I read some solutions online, and they dictated me to downgrade the `xserver-common` package. I did that, and after downgrading the `xserver-common`, I restarted, and this is what turns up. 

It just won't proceed forward from this screen. I need to restore it to fully functioning condition, since I have made a lot of changes on my Ubuntu 12.04 which take about 9 - 10 hours of work and I do not want to redo them. So, re-installation is not an option. 

Is there anyway I can get my OS working again. Also would the recovery mode help.I edited my GRUB default files in `/etc/defaults/grub` for not to display the recovery mode. So, if you can tell me how to boot up the recovery mode using GRUB CLI, that would be great. 

Also note, I cannot access tty1 on that screen and there wasn't any response, doesn't matter which button I press.

After pressing shift, I tried the GRUB menu, it still looks like this 

![grub screen after pressing shift](https://lh4.googleusercontent.com/-ewtkZqjSm_Y/UBOsUxc24jI/AAAAAAAAA5M/zh_NDqKpE4o/s1095/IMG_20120728_142516.jpg)

**EDIT**

That worked perfectly. I upgraded, the xserver-common. And then booted up ubuntu, it booted up to the login screen. But then it freezes. On the login screen. I cannon move the cursor nor the keyboard works. I can see the Ubuntu login screen, but I cannot do any thing. I tried going back to recovery but it bring me back to the same screen. I also tried failsafe graphics mode and still it brings me back to the login screen where it gets stuck.