I have a MACBOOK that i;ve installed windows XP pro on. when I try to get into it by using the FN+CTRL+ALT then backspace keys, it doesn't respond. this is a new mac and I don't know what else I need to try
Ctl-Alt-Del is "Control"-"Alt" (Option)- Fn>"Delete" on a Mac portable's keyboard.
You can also use Microsoft's utility to remap a del key on the keyboard as this is what the issue is. The utility is called remapper. It is located here:
You can also use a Windows USB keyboard and use the keys natively. This is normally what I do. But I also have a crap load of Windows Keyboards laying around.