My laptop recently began not starting windows.?

This is typical when a system has been affected by some malicious software (virus/worm/Trojan). The fix for that is actually reload your system. If you have done a backup of your system you can then restore it to that state.

Once done be sure to download all security updates provided by Microsoft. I would also recommend that you load a personal virus scan application like Norton or McAfee.

Now if this a new system (within the last two years) on the boot splash screen you should have an option on the bottom of the screen (F10 or F12) to restore Windows, this is a lot easier than finding your OEM disk that should have come with your laptop to restore your system.

You need to go to your safe mode. and restore you laptop to an earlier point that might help to fix your laptop, otherwise you might have got a virus or malfunction of you hard drive.

To go to your safe mode when you restart your laptop keep pressing F8 and then go to control panel and look for windows system restore.

so it doesattempt load up and restarts?

There was an older virus that continually restarted the computer.

Id try scanning it with a virus boot disk first