Yesterday I installed KDE through gnome in Ubuntu 10.10 and after some time I decided to uninstall kde manually through the Synaptic Package Manager. I completely removed all the packages which I thought were related to KDE and not critical for Gnome, but I was wrong as it turns out not only did I delete KDE I also deleted a lot of critical packages for Gnome.
I think I deleted at least half of the critical packages and now I do not have even a terminal and a browser. Also when I rebooted I could not even log in to Ubuntu so this my question: is there a way to repair Ubuntu?
Without a terminal of some form, it could just be one you get by switching to a tty (e.g. pressing Ctrl+Alt+F6) and a network connection you will struggle.
If you have access to these two things you should type
to reinstall all the packages installed by default.
If you can log into the text mode, you can still install gnome via apt-get. If you could not connect to the internet, you can download a ubuntu alternate cd. Just add the cd into your /etc/apt/sources.list. Then you can use apt-get. Also you can use a livecd and "chroot" to your existing ubuntu system. The methods listed above may be too difficult for you. So you'd better back up all your private data and application settings, and re-install ubuntu.