My XPS 14 not booting up

I have XPS 14 (with Windows 7 64 bits) since last 2 yrs.  Recently I faced this issue.

When I turn it on, it shows the Dell logo screen and then shows either of these 2 messages:

1. To insert media to boot

2. at time it shows - Disk Read error Press Ctrl+Alt+Del to recovery

I tried booting with my original Windows7 DVD. It boots up fine. I used Safe mode option and tried the Auto Recovery option. It tried to figure out the issue but didn't find any issue after more than an hr.

The issue still persist. it doesn't boot up from HDD. What could be the issue and how it can be resolved.

Thanks in advance.

Girish.