I've got a Cisnet CPU that continually runs the drive at high speed until the computer shuts off by itself. It won't stay on long enough to do a diagnostic. Any ideas on how to fix it?

All makes & models are different. You have to drive the car at several miles high speed, than several miles low speed & repeat the process. That usually covers most vehicle. But just drive normally at high & low speeds and soon enough you'll be good to go. Does not do the clock & radio for you. That your on your own.

The gas u put I'm the tank was high octain if it was it was making the engine fire to early replace the gas and it should wor properly

It appears you have a faulty CPU fan and it is causing the CPU to overheat and shut down.
I suggest you replace the CPU fan. remove any dust from the heatsink and put new heatsink compound on the CPU/heatsink.

see if this link helps you out. hard drive runs constantly Google Search

Try the following;

1. Press "Start" on your Cisnet computer's desktop screen. Scroll up to "Accessories," then hover over "System Tools." Click on "System Restore."

2. Click the option that allows you to select a different restore point, rather than using the default restore point. The program will display a calendar.

3. Select a specific point to restore your Cisnet computer to by choosing a date from the calendar display. Click the "Next" button to confirm, then click "Finish" to close out system restore. Your Cisnet computer will restart and open with the selected settings.

Be sure that you do not unplug your Cisnet computer while running system restore because it will need sufficient battery life to complete the program.

The cpu get overheated and will shtdown to protect it. The fan continues to run until a CPU safe temperature is reached / sustained.

1. Use laptop on flat surface, not on pillow, carpet, bed, etc. that will restrict air flow. Using a can of compressed air, clear the air vents.

2. If the symptom continues, then the heat conductive paste between the cpu chip and the heatsink is no longer effective (hardened, too thin, etc.). Remove the heatsink and add thermal paste
($6 Radio Shack).

I agree...sounds like a power supply problem. Typically a bad power supply will not damage the motherboard. It should still be functional.

can you tell us more about your problems? we cannot really help a lot unless you provide more details about you problem.

If the repair store said the CPU or MB is bad... buy a newer computer.

you should contact your service provider . THey should fix the problem. ok