My HP ZD8000 Laptop will not boot past the startup screen

My HP ZD8000 Laptop will not boot past the startup screen. What are the
chances that it is not a total hard drive failure and I will be able to
recover my data. It was acting very strange and taking forever to boot prior
to this. Now it does not boot at all. The hard drive light comes on and stays
on for a minute or so, then goes out and doesn't flicker again until I
Control/Alt/Delete. Which starts the process all over again. Is it Possible
there are corrupt files on the drive that won't allow Windows to load, and if
so how do I go about resolving the problem. I also don't have a boot disk for
windows. Any help given will be GREATLY appreciated. Thanks
--
Larry