Last night when I was trying to install Fedora Core 7 on a Dell Inspiron 1520, annoyingly I was stuck up at the Linux installation startup. The installation procedure had not even reached running anaconda. Instead it stuck up saying it did not recognized the DVD/CD drive and needs a device driver for the same. Here's the quick solution I adopted to resolve this. It might be helpful in for some other models of Dell too.
Create an iso of the FC7 Linux DVD. Copy the iso in a FAT32 partition on your hard disk. This needs to be done as it does not picks up the iso from ntfs drives. Now, when you start installing Fedora Core 7, it will again ask for the DVD/CD device driver. Instead select the source of your Linux as the partition having the iso image of the DVD. And it moves on to anaconda. :-)
Although after installation Linux was still not able to recognize DVD drive, the device driver can be downloaded and installed now as you have a working Linux ready. :-)