So, yeah. Dealt with Sony's support, and their answer (even though I wonder if that comment about physical HD problems is right, it IS a Maxtor HD I found out, and I've had problems with them twice, previously) was for me to order (not send me, me to ORDER at $17.95) their Restore Disc, which is the kind that wipes everything before putting on factory-setting software, so I get the fun and joy of updating everything again. (And potentially wait for the next HD failure, when I can _then_ wrassle a new HD out of them, most likely. Assuming the Restore even works correctly.)
Right now, when I boot it up without any assistance, it complains, "NTLDR is missing, Press any key to Reboot," so I know now that picking "Fixboot" was a bad idea. I can still use boot discs on my PC, and I think I spotted that my file partition is still there, I think, but I wasn't clear on how to reach them (most of the boot disks seem to be DOS-based, and XP stores files in a different format, right? NTFS, was it?), unless I was just missing something obvious.
So, I guess the question is, is there a boot disk available somewhere that'll let me network the PC to another I have up and running (another XP Media Center one), to see if I can copy my files off? Or is there some other way I could go about this? I'd rather not get into physically taking out the harddrive or anything if possible, since they might point to that and invalidate my warranty. I'd just like to try to save my 4-5 months of files, if possible.