how to retrieve files from my computer

Hi

You should be able to grab your files by booting into the recovery mode.

Reboot your computer
When the BIOS screen disappears, you should see the GRUB 3 second countdown in the upper left corner.
Hit the ESC key before it counts down to zero. This will display the grub menu.
Choose recovery mode, usually option #2
The system will boot up in text mode and present you with a console
You should be able to grab your files and copy them to a thumb drive or cd/dvd. Be careful, as you will be logged in as root.

Hope this helps.

a little thing to add:
In the recovery mode it will show you a text-based menu with various recovery options (including x fix, that you can try). The last one "log in as root" or so gives you a console and logs you on as root. To become an ordinary user, use "su [your username]" (or maybe try crtl+alt+[f1 ... f12] again).

i booted up in recovery mode, but i do not see a menu as you have specified; i am just logged in as root and can put commands into terminal and that's pretty much all i can do.

hmmm, I may have been wrong cos I use Ubuntu 8.10.
In any event, you can rescue your files now (either just mount a memory stick and put them there, or burn them on a CD or copy them on an external HD). Alternatively you can try the command "startx" or "kdm"/"gdm" to try to get your graphical interface up. That should tell you at least in an error message what goes wrong. In the command line, you can also use "apt-get install --reinstall ....." or "dpkg-reconfigure ....." to fix whatever is broken.
Keep in mind that you are root now, so you can easily break things. You can use "su [your username]" to make yourself your ordinary user.
Let me know if you need any help.

I could not get kde working, but i got my gnome working.

Thank you so much