I've never had that problem with my similar Vaio. Yours may be new enough that it does not have these problems the older ones have.
My thinking is that someone wiped the harddrive and installed xp from scratch prior to selling it. Thats why you didnt have the app for the function
keys. The only things that are working came from the xp cd installation. Following that logic, one can assume that there are other propriatary apps
that are not installed. Like the software that controls the fan speed when the cpu starts to get hot
I guess the first thing I would do instead of taking it to a shop and spending money, is go to
Sony's support site
and install all
If that fails I would probably go to the cpu mfg website and install their updated drivers for the cpu.
At the same time I would review the event logs for a clue to the exact cause of the shutdown.
Reviewing the bios setting wouldn't hurt either. Maybe disable the ACPI either in the bios, or windows.
If the time/date is incorrect after restart, it is probably your cmos battery.
Buy a can of compressed air and blast it thru the air vent to help clean the fan. Best to disassemble and do it, but they are a bit of a pain to get
apart. Dont unplug the keyboard cables they're fragile.
If that fails I would go start a chat session with Sony Support.
says they repair the problem for $150. But they don't specifically list your model as one
of the problem ones. They do give you a way to test
if its a hardware problem though.
To make sure that you don't have a software problem, boot a copy of the Linux BBC and type MEMTEST. If it runs
longer without croaking than Windows did, your computer is probably all right, and you need to find a misbehaving program. If it shuts down after
running for the same as with Windows, you probably have a hardware issue.
If it is a hardware problem, it could be either the cpu, or capacitors. These are
on some models, with only a few workarounds.
Only after all that would I consider spending money on it.
[edit on 5/26/08 by makeitso]