Can't get past initial login (10.04)

I think I just ruined my family's computer! Any help would be greatly appreciated....

The system appears to be accepting my user name password combination, but isn't letting me go any further.

Here goes: after running through the initial installation process for version 10.04, I enter in my user name and password, the screen flashes black for a second, and I get bounced back to the login screen.

I know I am using the correct user name and password, as 1) I just created it in during the installation process (it's very simple, definitely not making a mistake), and 2) When I have tried the wrong user name/password combinations to test, the system catches it immediately and says that this is incorrect info.

Background/possible clues:

I was attempting to replace XP. Rather than partition the disk and install them side by side to be safe, I was an idiot and decided do a complete replace, so I'm basically stuck with this.

I've reinstalled twice now and still get the same problem.

This is a laptop (4 or 5 year old averatec) that required the use of an external wireless card. I tried taking the card out during the second install with no result.

: Installing using the .iso method. Made the cd, followed all the instructions, etc.

I would really appreciate any advice....thanks in advance!!

Login problems

I have seen this caused by a full /tmp filesystem. It could also be that you don't have a /tmp filesystem so the root filesystem / could be full. The problem occurs because there is no room for the X Window system to create files in needs in /tmp. You should be able to login using one of the virtual terminals because a text mode login does not create files in /tmp. Simply press the key combination Ctrl-Alt-F2( or 3,4,5 or 6) to get to a different virtual terminal login session and you can login from there. Use the df command which will tell you the status of the filesystems. You may have to delete some files from the full filesystem. It is also possible that there just is not enough room on your hard drive (you do not say how big it is) or the installation did not use all of the available space. You might be able to delete some applications to make room.

Unfortunately it is not possible for me to be more specific based on the information you have provided.

I also suggest getting a good book about Ubuntu. It can help you with making good installation choices and ensuring that all of the disk space n the hard drive is used for Ubuntu.

Enter at the system using

Enter at the system using gnome safe mode. U probably won't be able to connect. Open terminal and type: nm-applet, this way you can connect. After this open a new terminal and type: sudo apt-get install selinux. Reboot your computer and try to logon in normal mode.