Will not complete boot sequeance

Several possibilities.

1. Your windows installation is corrupted. You will need to use your recovery CDs or the recovery partition to reinstall windows.

2. Hard drive failure causeing windows corruption.

3. Bad memory.

4. Bad motherboard.

Chances are, it is one of the first two. When you first turn on the computer, press repeatedly the F10 key until the laptop boots into recovery mode. It should automatically go to a place where you can do a soft recovery of the hard drive or, that is to say, a non destructive recovery, only removing the windows files and reinstalling the original windows files. This leaves your data intact. After the operation and if it is a success, you may have to reinstall some software programs again if they don't work but your data will remain in tact. If that doesn't work, do it again only when the recovery screen comes up, press the advanced button which will take you to a complete system recovery where it will reformat your hard drive and reinstall your laptop to its factory preset, just like it was the day you bought it.

If neither of those work, you need to get a program that will run a scan on your hard drive to check it for errors but, normally, the first solution will do just fine for you.