If you mean a Windows logon password, there are several free utilities to do this. The ones I know are based on BartPE; in other words, you download software to burn a boot disk based on your own Windows system.
I have used the password reset gadget on the old free version of EBCD on Windows XP. You can find it at http://www.simtel.net/product.download.mirrors.php?id=80024
, or an equivalent Simtel mirror.
UBCD for Windows also has one, which I haven't tried, but I have used other utilities on the CD. You can download it at http://www.ubcd4win.com/
In addition to problems with some installations of Windows, Bart PE sometimes has problems with finding the hard drive on some laptops. If that happens to you, you'll just have to install the correct drivers.
If you mean a BIOS password, UBCDforWin has a utility to reset it, but I've never tried that either. Some laptops have a way of resetting the BIOS password with a jumper, as desktop machines do, but some have more complicated systems which usually involve a paid support call to the manufacturer.
If you have the driver problem, or if you have trouble finding the password repair utility, just post again here, and people will try to help.