CentOS

First off, I am very new to Linux and especially CentOS, as I need to use CentOS for research this semester.

I installed and have been running CentOS 7 with gnome for the past two weeks with no problems. I usually just keep the computer locked in the lab I'm working in, and never needed to do a full reboot until today (not due to any issues, just had to leave the computer off for the night). After rebooting, I try to log in (I have root credentials, but I log on as a user), and after trying to load the desktop GUI, the system just kicks me back to the log in prompt.

I tried Ctrl+alt+F2, changing to root, then running "startx" and I was able to start up the desktop GUI as root. However, I don't want to operate as root for obvious reasons.

How do I fix this? Also, I have been teaching myself most of this, so if responses could be as explicit as possible, that would be very very very helpful.

Thanks!

Reboot, login as the user and watch it fail. Switch terminals, login at the command line and look at the various logs under /var/log. Running ls -lart /var/log will show you the most recently modified at the bottom. Read those first.