I upgraded Linux kernel on Ubuntu Feisty from 2.6.20-15 generic to 2.6.20-16 recently...but after I restarted the machine...it showed up with "Starting up" message n nothing further...I tried getting into recovery mode...it also didn't work...as after booting up...it stopped midway along themessages "PCI quirk...region interrupted"...thankfully I was able to boot into my prev kernel version...I looked up online n came across Alberto Milone's envy...I tried running it but it also didn't wotk as I was unable to get into the recovery mode of the latest kernel version! BTW, my graphics card in NVidia GEForce 2 MX/MX 400...

I have no idea as to how to go about fixing this problem...apart from removing the latest kernel...any insight/advice as to what to do next to solve this issue would be very helpful...and thanks in advance...

I have found a solution.

Boot with new kernel. When desktop manager hangs, switch to text tty (press Ctrl+Alt+F1), log in and type
sudo apt-get install --reinstall linux-restricted-modules-$(uname -r) nvidia-glx
This will reinstall linux-resticted-modules for current kernel version and nvidia drivers.
After that, type startx to start X Window System.

Well, if you have changed "nvidia" to "nv" in xorg.conf, you should change it back. Non-proprietary driver ("nvidia") works better.

Thank you for answering my query! Unfortunately since I can not get into the text tty...there's no way I can test the solution u offered...so my query now changes to as to how to either get into recovery mode of the latest kernel or into the tty text mode thru regular mode...any suggestion or advice would be welcome!
Once again...thanx for taking time to answer my query...I appreciate!

As I understood, Ctrl+Alt+F1 did not work?

Well, you need to log in to edit your configuration files. There are several possibilities: you can select previous kernel version in boot menu (usually there is a pair of line per each kernel), or you can start the last kernel in recovery mode, or boot up from LiveCD.

After you logged in, edit /etc/X11/xorg.conf file (if you logged in with graphical interface then you can use gedit or kate or anything; in text mode I use vim, but vim is not easy to learn).

1. Create backup copy:
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.bak

2. Open file for editing:
gksu gedit /etc/X11/xorg.conf

(if you have booted from LiveCD, there would be path to the file on your mounted Linux partition, something like /media/sda4/etc/X11/xorg.conf)

In this file, you need to change line
Driver "nvidia"
to
Driver "nv"

The line is located at Section "Device".
"nv" is standard Ubuntu driver for NVidia cards.
Save the file and reboot in normal mode with the last kernel. X Server should start now.

Then - after you boot with the last kernel and log in - perform all that stuff with reinstalling driver:

sudo apt-get install --reinstall linux-restricted-modules-$(uname -r) nvidia-glx

After that, open /etc/X11/xorg.conf and change "nv" back to "nvidia". Reboot.

Glad to help you.
By the way, are you Russian? :)