I have a HP 650 laptop with windows 8. I installed Ubuntu 13.04 and removed it afterwards. I can get into windows 8 through secure boot, but if I disable secure boot, to run from CD or anything else, it goes straight to a grub screen which asks for commands. I really need to get rid of this bootloader.
Take a look at this answer from Rod Smith on my question earlier this month. It explains how GRUB should be removed properly. I faced the same problem where I couldn't get rid of GRUB after removing Ubuntu.
Though, if you are wanting to dual boot with GRUB and Windows 8, you should use the boot repair tool and run the recommended scan/fix.
Also note that you may gets some bogus GRUB entries for Windows recovery options that may actually boot to windows itself while the main Windows 8 entry will only give an error, so you may have to try each and see which one is for Windows.
You can then remove the bogus entries once in Ubuntu through a text editor (ie: Vim, gedit) or using a graphical frontend like