Pc (HP) stop working abruptly;green light on back on; mouse and keyboard don\'t

[pne121]

HP PC stopped working, power light and green light on back of pc on but keyboard and mouse not working light on keyboard and mouse not one.

 

[zerrith]

HP PC stopped working, power light and green light on back of pc on but keyboard and mouse not working light on keyboard and mouse not one.

When did this happen? Did you boot up and it wasn't working or did it stop working while the machine was already booted? Have you installed any new programs or hardware recently? You can try booting into safe mode or a clean startup and see if it works. Also, how old is the PC?