Many thanks for your suggestions. They are wellcome.
I wrote recently about a problem at the beginning of instalation of RH. I explained that my computer left hang up when RH asked me about media where I have the packages to install.
Before of all, say that I have test the solution of Boot with diskettes and the problem is the same.
I have tested the suggestion of JMS about check the BIOS messages at bootup (because of the posibility of the CDROM interface was sharing an IRQ with my SCSI adapter), and I'm going to say what computer show me at bootup:
PCI Device Listing...
Bus No. Device No. Func No. Vendor ID Device ID Device Class IRQ
0 7 1 8086 7111 IDE Controler 14
0 7 2 8086 7112 Serial Bus Controler 11
0 10 0 9004 7178 Mass Storage Controler 10
1 0 0 105D 493D Display Controler 9
The thing is that when I disconnect the CDROM of the IDE 1, the installation goes fine but I heve not CDROM then.
Does anyone know how can I solve that?
Another curiosity: When I turn on my computer with power button, CDROM is not detected at bootup. When I boot my computer with Ctrl-Alt-Supr keys CDROM is detected at bootup.