Problem loading disks.Help!!

Hello,
Could somebody help me please,,when im putting disks into my tower it wont play them.I have tried all the settings on my computer to play the disks automatically.It used to work and the option to play came up straight away,now it hyas just stopped working altogether.I have also tried reseting the computer back to an earlier date but this has not worked either.Has anyone got a possible solution for me and if so would you be able to tell me step by step instructions please.It is a Intel 2 core processor.Acer,aspire.Thanks.