Hardware

If the laptop is experiencing these issues while processing something you may want to check the intergrity of the HDD. Most have an HDD check in BIOS. Otherwise check the manufacturer website and you may find a tool. You can also run a Checkdisk with the options to fix and recovery bad sectors. If this increases stability I would say your drive may be an issue.

If we're talking about over heating, you can monitor the temp. Some BIOS have this option. Otherwise look for software that will do so.

Let us know if you are unsure how to do either and I'll send you more detailed info

but you haven't given us the full story, remeber you are our eyes and ears and you must be specific about what occurs in this scenario.
For example does the computer display any error messages when turns off? does it restart itself automatically? when you log back in do you get any messages on screen like "windows has recovered from a serious error"?
When you reinstall windows the partition is formatted but if there is a problem with the partition structure you need to delete the partition during the setup and create a new one. However there are several reasond why a laptop might behave like your daughter's and we will need more info to help you
Cheers

to run two antivirus programs are you. If you are it isn't a good idea as they will try to compete. Dice one of them by using the Add Remove Programs feature.

It could also be overheating again and if you feel that you are competent you can try this.
I would give the inside of the case a blowout with compressed air. When blowing air through the fans make sure that you physically stop them from spinning, as they may generate power and cause damage.

Next, remove the Heatsink, give it a thorough clean with a cotton cloth and reseat the CPU applying new CPU grease. Arctic is a good brand.

If the Fans spin freely when you give them a spin they are probably OK. If there is resistance replace them.

Clean the Cooling Vents

Depending on the model, vents can be found on the side, back, and/or bottom of the notebook PC. These vents allow air to flow through the PC and keep it cool. Buildup inside these vents impedes the cooling process.

Clean I/O Ports

The back of the notebook PC has a series of ports. After cleaning the cooling vents, take the compressed air and **** out any debris that may have accumulated in and around these ports.

Clean the RAM

Clean the golden edge of each memory stick with a soft rubber/eraser, remembering not to touch the golden edge of the memory stick. Check with one stick at a time, remembering to disconnect the power from the PC.
Laptops run fast microprocessors that can generate a lot of heat. The heat is mainly vented out of the bottom of the laptop but ventilation effectiveness is reduced when the laptop is placed on a solid surface. A hot laptop can suffer from reliability problems and a system that overheats can fail.

Adjusting your power options will help your laptop from heating up when not in use even if for short periods of time. You can set your hard drive and display to turn off after a set time period. Another option is to set the laptop to go into standby or hibernate mode.

One way to help in this situation is to use a Notebook Cooling Chill Mat, something like this.

http://www.ao3.com.au/product.asp?manufpartno=AWE11US

The first is the Actual HDD and see if it is working correctly. Test with the Makers Testing Utility for correct Function of the HDD. Naturally here you'll need to pull the cover over the HDD to find out who made it then just click on that name in the link below to get it's Makers Testing Utility. This is a Name like Seagate, Samsung and so on defiantly not Acer.

http://www.tacktech.com/display.cfm?ttid=287

The next thing is it could also be a Heat Issue occurring here as well. You need to look at the Fan/s on the bottom of the NB and make sure that they are working in the first place and secondly that the air intakes are not being blocked preventing the fans pumping air through the NB to cool it.

If the unit gets hot while you are using it I would also recommend a Cool Pad like the one shown here

http://www.antec.com/Believe_it/product.php?id=NzI=

Using one of these will help to prevent the unit overheating and sucking in Dust and other contaminates that adversely affect the cooling of the unit. Personally I refuse to sell any NB without a Cool Pad as it's not worth the problems that do occur.

Col

luismolina,
I was thinking that a virus had corrupted XP, and had not considered it to be a H/W problem.

tintoman,
When it shuts off it's like it completely lost power all of a sudden. It does not restart, and when you restart, it goes into the mode: "I shutdown wrong and I must do a disk scan", before it boots. There are no msgs when it boots, after the disk check.

Jacky Howe,
I'm not running two virus scans at the same time. In fact I ran AVG first, because that's what I use,and it bombed. I uninstalled it and installed Norton, because it came with the recovery disks, and it also bombed.

I want to thank everyone for your input on this problem, but what I decided was to take it to a different shop. The tech booted it with a dos CD and it shut off, so it?s probably a H/W problem, and I?m not comfortable dealing with that, so I left it with them last night. I should know tonight what they found.

I think either Heat or Power issues.

The first time you got it "fixed" di dthe guy fix the heat issue? what did he do?

Make sure all your fans are still working and it wouldnt hurt to get a can of air and spray it into the vents and fan ducts.

about the power, try taking out the battery and plugging the power into your wall.