Linux Mint 15 failed to start X Server

[Guest]

Hi guys,
My son was messinga round on my Linux computer and was trying to change the login screen. He then got an error message saying Failed to start the X Server. I shut the system down and then loaded it up. Then, I got a different login screen and I coudn't type or click anything. Please tell me what I should do if you know - Many Thanks
AKNerd

 

[skittle]

check /var/log/Xorg.*.log
also try gdm/mdm/lightdm whatever display manager you use and see I'd it starts without errors

 

[Guest]

How do you do this?

 

[skittle]

Post the contents of /var/log/Xorg.0.log here, you can copy it to a flash drive or something.