I am trying to install Fedora core 1 (with GRUB) on the following pc :
Asus P4B with latest bios upgrade, 256 Mb ram, Maxtor 80 Gb harddisk, Intel PIV 1.5 Ghz. Installation works fine, but at the end of the process after the graphical screen disappears, a lot of these text messages show up : rpm, fatal region error, run recovery
You might try checking the consoles at various points during the install. If you press Ctrl+Alt+F1, for instance, you'll switch to console 1. Debugging information is printed to the 3rd, 4th, and 5th consoles, IIRC. The GUI should be back on the 6th or 7th. See if you can track down at what point during the install those errors are first printed.
You might also want to format your partitions and check for back blocks during the process. It'll take a while, but it'll be worth the time to spot a potential problem.