The disc error is a common sign there are hardware issues with the machine.
I suggest you post again in the CNET Computer Help forum along with all the things the forum asks you to post such as make, model, age, recent repairs and maintenance. If none, then tell that. A 4 year old PC with no hardware maintenance should do what you are reporting.
My computer sayspress ctr alt del to restart. System boot error.also sometimes says disc error. My anti virus charter no longer works. It says service no longer running?I somehow got it to log on. What do I do now?its a sony. Windows xp 2002. Please help.