I have a HP pavillion zd7000 lap top that is just a little over a year old. For some unknown reason it started shutting itself down for no reason. Sometime it will go 2 to 3 hours before it happens and sometime it will shut down after 15 minutes, after re-start. Any of you computer guru's have an idea as to what could be wrong. I have cleaned the two cooling fans and that seemed to help somewhat, but did not stop the problem. I have claims to close and this is making it difficult. Any suggestions?

For less technical procedures to find out the cause, try:
1. Did you add a new program or new device to your laptop?
if yes, it may be conflicting with your drivers, video or motherboard.
if not, then
2. You may have a malware, virus - a program that is running an unnecessary process(es) that is(are) forcing your cpu to overwork.
if yes, press (ctrl, alt, delete) and see if you have any odd processes or use a spyware, antivirus.
if not, then
3. As previous post suggested - overheating- you may try air blowing the motherboard not just the fans and/or buy a cooling plate for your laptop. (BestBuy, etc.).

The evidence of sporadic shutdowns you described, points to - overheating.
Since, this is happening quite often, start backing up your important data.

Thanks to all. I am trying the things you suggested. I also ordered a cooling pad for it. I have had several laptops that have run successfully for 5 years.

Tom, if overheating is the problem (Toshibas like mine are notorious in this regard), cleaning the fans is not enough, as much crud can build up on the processor's heat sink. It's most likely a heat problem if all of a sudden your laptop dies completely with no warning screens at all, while emitting a distinctive winding-down sound..

Windows Task Manager will show you what apps and processes are running at any given time. Check often to see what is consuming resources: You may be able to remove items from your start menu that are taking up CPU cycles unnecessarily (for instance, an anti-virus or spyware scanner, or Windows Explorer [not to be confused with Internet Explorer]). Task manager allows you to selectively terminate applications and processes. Mistakes can cause momentary terror, but are rectified automatically by restarting Windows. It is probably the norm to have 50-60 or more processes running at any given time. Make sure your hard disk drive is defragmented. In the event of a hard drive replacement or reformat, consider disk partitioning. I also often prop up the back of my laptop with a spectacles case for better airflow (usually making sure that I'm not actually covering one of the fans...LOL).

If your laptop does shut down without warning, and you suspect overheating, it's probably a very bad idea to attempt to recover right away, as the boot cycle and start menu heartily consume resources, resulting in an even heavier heat burden. Better to wait until everything cools way down. I have even placed my laptop upright in an opened-book configuration in front of a room fan directed at the computer's fan vents, in the hope of dissipating residual internal heat more quickly. Today's processors generate tremendous temperatures in the compact laptop environment and are capable of committing suicide (and / or frying other circuitry).

It's also a good idea to completely restart the computer from time to time. My laptop starts behaving strangely after a  few hours of continuous use. Long hibernation and standby modes can also provoke annoying output.

Finally, when you eventually restart the computer, even if everything seems copacetic, back up anything important on your computer that has been added or changed in the time between your unrequested shutdown and your last system restore point (in XP) . Then use System Restore to go back to a point before the suspected heat attack. This should, at least in theory, help keep the number of corrupt system files and registry entries to a minimum. (Sludge tends to accumulate, and the skills required to safely remove it are not in the average user's repertoire). Note: Many Windows applications (Oulook, for instance) save changes to your chosen restore point automatically.