First, I apologize if this is a redundant thread, but this problem has been driving me crazy ever since I got this netbook. When I got the VAIO, it came with Windows XP pre-installed (no surprise there). I tested the system with the existing OS and ran into a problem whenever I tried to reboot. The system hangs with a black screen (powered completely off), with everything else still running. I tried installing all of the updates for Windows and VAIO specific drivers from Sony's website, but the problem still persists.

Thinking that it was only a Windows problem, I decided to wipe out Windows and install Xubuntu. The system still doesn't reboot properly. It will suspend, hibernate, and shutdown, but it will not reboot. I've already tried Fedora, Zenwalk, Pardus, and Mandriva. They all have the same problem. So that means that the source of the problem could be the hardware itself. Any help with this problem would be much appreciated. Also, if it happens to be BIOS related, then how would I go about safely flashing the ROM? Would my problem go away if I install CoreBoot?

how do you reboot? remove battery, wait, reinsert, then power button?
after restarting in xp, Start button> Run "eventvwr.msc" (eventviewer). often that gives clues to trouble.
it also sometimes gives clues to trouble that's not otherwise noticed.

You didn't read the whole post, WinXP is completely gone

And when you did your installations from a CD, would it reboot after it or not?
If NOT, then it must clearly be a hardware problem and it should be brought to where you bought it from.

Yet does it work fine apart from rebooting? Cause if you didn't buy it and can't return it back, then this being unable to reboot isn't that terrible a problem, unless it should produce some undesirable consequences.

Well, the netbook doesn't have a CD-ROM drive, so I ran my installation tests with Unetbootin and a flash drive. Every time a reboot was requested, the problem occurred.

Your right about the problem in general, it does everything else EXCEPT reboot. Though it doesn't have much of a negative impact, it is still quite baffling, especially since the problem doesn't care what OS you have. Since this is my first experience with a Sony product, I don't know if it's a sign of things to come or what.