a disk read error occured
The problem is that the computer's motherboard and hard drive are not communicating. The computer says, "I can't read the hard drive", therefore, the operating system (Windows) can't start.
Unfortunetly, this error can have any number of causes, so troubleshooting is trial and error.
Various remedies can usually be attempted by booting the computer from a Windows installation DVD and accessing the WinPE environment (a repair console built within the DVD) or if the computer's manufacturer has included a diagnostic partition on the hard drive (Dell usually does) , via F8 key -> Advanced Boot Options-> Repair Your Computer.
You are unable to boot from the DVDROM and unable to access the Advanced Boot Options menu; therefore, from a far, I can not help you solve this problem.
My recommendation:
- If the computer is still under warranty, have Dell remedy the situation.
- If not under warranty, take it to a local computer repair shop.
Good luck.