CentOS reboot failed, always respawn, how to solve

CentOS reboot failed, always respawn
CentOS installed MySQL, according to the internet, changed the INIT.D, increased the datadir= ... The path is there, I have verified it.
Said to be restarted, but the reboot failed, the display stopped at Init.d,datadir=...,command not found, always respawn
Keep hatching the thread, then the error, then kill the thread, and then continue to cycle. Unable to enter the graphical login interface.
I'm loading CentOS 6.3, which is a developer environment configuration.
Now I can't enter the system login interface (enter username and password)
There are a lot of software, as well as my installation experience, really do not want to re-do virtual machine.
Help, ~~~~~~~~~~~~~~~~~~~~~~~~~~.

------Solution--------------------
Is it not configured well?
[Root@sample ~]# chkconfig mysqld on← set up MySQL service with system boot from boot
[Root@sample ~]# chkconfig--list mysqld← confirm MySQL self-booting
Mysqld 0:off 1:off 2:on 3:on 4:on 5:on 6:off← If 2--5 is on the status OK
[Root@sample ~]#/etc/rc.d/init.d/mysqld start← start MySQL service

Initializing MySQL database: [OK]
Starting MySQL: [OK]
------Solution--------------------
Like this situation, really can not get into the way, only re-installed!

