You can look in the archives and try what was suggested in thread
"Installing SL 4.5 on machines with SATA hard disk" from 12 of November.
If nothing there works you can try and specify the following boot paramet
ers:
"all-generic-ide" and "pci=nommconf" - you will write the line: "linux
all-generic-ide pci=nommconf" when starting the installation.

Radu