Computer Diagnosing Help..

In the matter of one week, three of my laptops have either gone completely out or are having problems. 

I started laptop I use for school work and did a system restore on it and the first one didn't take so it told me to do another system restore.  After that restore was complete, the computer booted down and will not come back up.  When I plug the power supply into the laptop, it will completely shut off the power supply adapter.  In talking with some people who are familiar with computers, it might either be the motherboard or the hard drive.  I am just hoping at this point to be able to get all my data off the hard drive.

The laptop we use for our photo buttons for the portrait studio is now blinking a weird icon whenever I plug the adapter into the computer.  It is running off the A/C power, however the battery is not charging.  I am researching as to whether this is just a warning that the battery will no longer charge but the computer will continue to work off the A/C adapter.  I'm hoping that is all it is!

Last night, my husband plugged in his computer which we use for our portrait studio work and the first HP boot up screen comes on, however it then goes to a black screen in which the cursor blinks twice and then stays black.  It seems like it's freezing at that point as the wireless light doesn't come on and the computer won't fully boot up.  I am again researching this problem through the HP website and hoping it is nothing major.

I am almost wishing now, I would have taken my IT Tech certificate program first vs. my web design as it looks like with our luck, we need some major help with our laptops.