First, try performing a Microsoft System Restore, boot up the unit, hit F11 on POST and see if it does load the HP Recovery Manager (Beware it can take up to 3 minutes before it actually displays something!). If it does, click the Advanced Options in the bottom left screen, and then click "Microsoft System Restore", and then hit next, after it tells you it needs to shut down the HP Recovery Manager.
In the next screen, after loading for 30 seconds, click next, and choose a System Restore Point. Click on next two or three more times (all options are default and you do not need to change those) and then wait untill it is done and asks you to reboot.
If all the above fails, reboot, go into your BIOS using F10 (click it a few times on your POST screen), then, click "Diagnostics" at the top, and perform the Hard Disk Short Self Test (You might need to click on Smart Support first, but normally not with a notebook from HP). Let the system scan the hard drive, and if it is giving any errors, you might be looking at a defective hard drive and you need to call HP so they can send you a new one, and also some restore discs if you not already have them. Let me know how this turns out.
