I had a Pentium II 300MHz running Debian GNU/Linux sarge that I upgraded last month to an AMD Sempron 2800+ : I stuck the very same hard drive in it. I didn't have to configure anything except the ip addresses of the network interfaces (names like eth0, eth1 had changed) and the cdrom device name (hdc -> hdd). It's still running perfectly although I plan to reinstall to take advantage of the amd64 architecture.