Shuts down my laptop shuts down like every 20 minutes when am using it, if its on and am not using it..it stays on all day. it doesnt give a warning., it just goes blank screen

The fan running and staying on after the vehicle is shut off is sometimes normal to a point. Meaning that if an engine is to hot, low on coolant then the fan will come on and stay on to help cool the engine down after the vehicle has been shut off. But for it staying on for 20 minutes is not right either. I would wait and see if it happens again, if it does then I would have either a Mobile Mechanic or a shop look at the car to figure out why it is staying on.

check temp, then virus check control. alt. del. on how hard the mashin e is working if mashine is ful of hair in the fan......clean.

“My Toshiba laptop suddenly shuts down by itself without any warning. Sometimes it works fine for hours, sometimes it shuts down in 10-15 minutes.” This complaint we hear from our customers over and over again. About 15-20% of all Toshiba laptops we get for repair, suffer from an overheating problem. Yep, OVERHEATING!
This is one of the most common problems with Toshiba laptops we deal with.
Indications of laptop overheating problem:

1. The keyboard and the bottom of your laptop are very hot when the laptop is working.
2. The CPU fans are working all the time at maximum rotation speed and operate much louder than before.
3. The laptop suddenly shuts down by itself without warning. When it just started, the laptop was shutting down after 1-2 hours and how it shuts down after 5-10 minutes of operation.
4. The laptop works fine when it runs idle, but shuts down as soon as you start using any memory demanding applications (DVD player, image editing software, video editing software, etc.).

Solution:
If the CPU heatsink is not clogged with dust and lint completely, you can use canned air and just blow it inside the laptop through the openings on the bottom and on the sides. It’s nice as a precaution measure, but it might not work if your laptop already has a problem and the heatsink is completely clogged.

1. Open the laptop case, so you can access the CPU fan and the heatsink. In some cases you can access the heatsink through the latch on the bottom of the laptop. Sometimes (for example Toshiba Satellite A70/A75) you have to open the laptop case all the way down.
2. Carefully disconnect the fan cables on the system board and remove the fan. If the fan makes unusual sound when it spins (grinding sound), I would recommend to replace the fan.
3. Clean the fan and the heatsink with compressed air.
4. I would also recommend removing old thermal grease from the CPU and applying new grease for better heat conductivity.

“My Toshiba laptop suddenly shuts down by itself without any warning. Sometimes it works fine for hours, sometimes it shuts down in 10-15 minutes.” This complaint we hear from our customers over and over again. About 15-20% of all Toshiba laptops we get for repair, suffer from an overheating problem. Yep, OVERHEATING!
This is one of the most common problems with Toshiba laptops we deal with.
Indications of laptop overheating problem:

1. The keyboard and the bottom of your laptop are very hot when the laptop is working.
2. The CPU fans are working all the time at maximum rotation speed and operate much louder than before.
3. The laptop suddenly shuts down by itself without warning. When it just started, the laptop was shutting down after 1-2 hours and how it shuts down after 5-10 minutes of operation.
4. The laptop works fine when it runs idle, but shuts down as soon as you start using any memory demanding applications (DVD player, image editing software, video editing software, etc.).

Solution:
If the CPU heatsink is not clogged with dust and lint completely, you can use canned air and just blow it inside the laptop through the openings on the bottom and on the sides. It’s nice as a precaution measure, but it might not work if your laptop already has a problem and the heatsink is completely clogged.

1. Open the laptop case, so you can access the CPU fan and the heatsink. In some cases you can access the heatsink through the latch on the bottom of the laptop. Sometimes you have to open the laptop case all the way down.
2. Carefully disconnect the fan cables on the system board and remove the fan. If the fan makes unusual sound when it spins (grinding sound), I would recommend to replace the fan.
3. Clean the fan and the heatsink with compressed air.
4. I would also recommend removing old thermal grease from the CPU and applying new grease for better heat conductivity.

it sounds like the afc the fan control not working could be dust on the afc

it is most likely overheating that's why it's shutting off...

I THINK ANY VIRUS MAY BE IN YOUR SYSTEM. PLEASE FULL SCAN YOUR COMPUTER THROUGH A GOOD ANTIVIRUS. IF PROBLEM REMAINS SAME THEN YOU HAVE TO CHOOSE FORMAT WINDOW AND THEN REINSTALL WINDOW.

you may have your dim switch on and this cause the lights to stay on but they don't stay on all night or day they have a 10 minutes delay switch after 10 minutes they go off but yes there is an open circuit can be a door can be the trunk or the dim switch look for it and try to find the source of this open circuit like a mention before it's on the doors or the dim switch

Sounds like thermal problem.Debris in the fan or heatsink