I forgot my old password for Ubuntu. I accessed the GRUB page. The page is empty. I was ready to wipe the laptop and re-install Ubuntu. With another computer I downloaded the latest Ubuntu version and burned it to a CD. Now the laptop does not boot from the CD, and the GRUB page is empty. Advise will be welcome (before I put a 5Kg. hammer to the laptop). Thanks.

No need to reinstall for a forgotten password. Have a look here

Also, what do you mean by "the GRUB page is empty"? Are you not seeing any boot options? Will it boot to the Ubuntu you forgot the password for if you let it boot normally?

I mentioned twice that my GRUB page is empty. Nothing else can be done except re-install

The GRUB page dous not show any option to choose from. Only grub grub grub grub grub grub grub grub
If I do nothing when booting, I get an option to log on as a guest.

Enter into your laptop boot menu and set it to boot from a media drive such as USB or DVD and get it to boot off of that first. If you are constantly stuck at a boot menu from the broken install, then the first thing to do is to figure out how to get the laptop to boot off of another media.

I did that. It looks like it is the old boot menu. I set it to boot from the CD but it still boots from Ubuntu.
How do I figure out how to get the laptop to boot off of another media?

There should only be one boot menu for the PC BIOS. This is the boot menu I am talking about. The PC specifications would be helpful to know. Most systems will enter BIOS using ESC, F10, DEL, or some other key during the initial boot.

When you say it looks like the old boot menu, this is confusing. Are you saying that it boots into Ubuntu? Because an install media disk will also boot off of that disk, what is called a Live Boot Media, so you can see how that version of Linux will look and run on your machine. So if you are seeing it boot fully into Ubuntu, it may be booting off of that CD.

Ok. I checked again. The boot menu is holding the setting of CD boot first. If the boot is from the CD, it doesn't help much, since I get the same screen asking for a password. I need to re-install. How can I do it from a Guest login?

There should be no password for the version from the Live CD media.

Where did you get the ISO to make that disk, or where did you get the disk?
What version of Ubuntu are you trying to install?
What are the specs for your PC system?

True. Proves that the boot is still from the Hard disk.
I downloaded the latest ISO today from the official Ubuntu site, to my desktop.
Then I burned it to a RW DVD . I tested the DVD and It shows many files, not the ISO file. this proves to me that the burning is OK.
Now I did something else. I set the laptop to boot from USB and restarted with a Windows 8 setup USB. Windows 8 is now installing. I will decide later if to hold on to Windows or to try Ubuntu again. I promise to keep a record of my password.
Thank you all at the Forum for trying to help. I is not your fault that I have a lousy laptop (Fujitsu Lifebook LH532 from 2011).
Jacob.

When you say "burned it to a dvd", what did you do? If you burned it like you would files then it will not work. It needs to be burned as an image.