Before you use UBCD, take a look at this:
http://h10025.www1.hp.com/ewfrf/wc/f...name=c00678968
If you have the CDs that came with this laptop, then you can use those instructions. If not, take a look at this:
http://www.techsupportforum.com/841779-post3.html
Those instructions should be standard.In your case, you will want to perform a destructive recovery (destructive meaning it erases your current Windows installation).
You're welcome.