Wubi is either loved or hated. Personally I didn't care for it but many good people have reported it as wonderful.
It has some limits to how it guesses it should boot it my complaint. Could be some issues with your computer, some bios settings too fast or off a bit. Memory issues may cause it or drivers. Any sort of thing could cause it like those in a normal install might fail.
If you have a newish system consider a virtual machine instead. If you need a native install then consider a dual boot. Be sure to uninstall what you have from add and remove programs in xp.
Is your tag line a sort of a sales pitch?