Read disk error occured during rebooting

Question

The model of my PC is ACER Aspire e571 which was bought last October 2007..recently i encountered slow response in every applications that i want to work on and was frequently shutting down unexpectedly while i'm at the middle of an application. so i consulted that issue to an IT technician was told me to try to recover using my recovery disk..and when i finished the first disk and was adviced to insert the next disk..it so happened that the said disk cannot read and ejected. I tried many times of inserting the next disk but unfortunately not accepted. Later i pressed the ESC button to leave the said application but it wasnt rebooting and was described as...read disk error occured.

Please help me to resolve the issue. Am looking forward for any help you can extend. Thank you and more power.