Only ROOT can goto KDE now

Good Hard drive install - All working great - Downloaded a simple file and saved to desktop folder - Now users cannot log in past the KDE log in screen - At the log in screen all looks normal - Then when logging gos to simi grey with mouse pointer at the center and then right back to the KDE login screen again - Root log in stil works fine - Also the users can still log in via consol but cannot get past "startx" to get into KDE - This Knoppix hard drive install has been the very best with my limited knowlage but man - Where did this KDE fualt come from... Can it be fixed or do I have to do another install to get back to my user desktop...

GOT-IT - I could only log in as root - Went back to the screen and logged in useing the consol option in the bottom right hand corner of the KDE login screen - Then logged in as user that would not work in the KDE login screen - Then entered "startkde" - Well then it went into a script finally indicating that my particular user name no longer had any room left on disk - Well - Logged in useing ROOT then went to Home then went to that particular user file and deleted the contents of serveral files I had downloaded and left on my desktop and a few programs I had downloaded into the temp directories - After halting and starting again I was able to enter as user again everything back to normal - BRAVO Knoppix - I probably never would have had this problem if I was useing a hard drive bigger than 2.5 gig - Of course I still have the other hard drive with all my windows stuff on it - Hummmm...

THANK YA-ALL