Okay – so I’ve been reading posts on this site for a couple of hours. I have a ca. 2005 Sony VAIO RZ44G P4HT with AMI BIOS (v2.51) and have not updated anything except that I have Windows XP Media Center w/SP2 updates. the original HD is a 160GB partitioned C/D drive but the C partition was down to only a few hundred MB of space even after clearing out all the accumulated flotsam and jetsam. I put in a Western Digital Caviar 500GB with the jumpers configured to run the ‘original’ drive as master and the ‘new’ drive as slave and now windows will not boot. There was no prior functional issue with the original drive and I’ve never had a boot error before in several years – the machine has been bulletproof. Now when I enter BIOS it does not detect either of the hard drives (although when the computer attempts to boot, the original drive spins up and appears to be operating through the power up screen where it flashes “SONY” and “P4HT” then it spins down and I get an error that says “Reboot and Select proper Boot device or Insert Boot Media in select Boot device and press a key” I have not yet used my work laptop to attempt to download and run any boot software b/c I’m thinking that I should still be able to boot from the original drive and it doesn’t make a difference anyway if the BIOS can ‘see’ either drive, right? The issue is that the AMI BIOS will not let me manually search for or create a hard drive…it only has “AUTO” “CDROM” or “ARMD” settings….and it won’t find the drive on AUTO…when I F2 into the BIOS at startup, the system appears to be reading and listing the 3 drives (perhaps the C/D and new drive?) just before entering BIOS but I still can’t ‘see’ the drives in BIOS or get around the boot error. In addition, I’ve used F8 to try and force the system to boot off the original hard drive (listed as Sony UMH-U HS-MS) but I still get the boot error message…..somebody help me, please????!!! Going nuts here….Thanks in advance.