i dont think that maters...just make it auto play so when u do cd boot it will work.

auto play and bootable CD are completely different. Auto play will work if u already have windows installed, while bootable CD will work even if u don't have windows installed and want to repair/reinstall windows. I don't know how u copied the bootable CD onto ur comp? If you used nero or some similar software to create an ISO image on ur comp then u r good but if u simply copied all the files/directories on the CD and pasted it on ur comp then it will be very difficult to make a correctly working bootable CD. Basically if u created an ISO image, then use a CD burning software to simply copy the image onto a CD. If not, then usually all CD burning softwares have an option of making a CD as bootable when burning the CD, so try to burn with that option selected but most likely the CD won't work correctly after burning. Let me know if this helps.

I have nero 7 for burning the CD but I do not how to make it and what is an ISO image and how to make it

so if u have the original windows xp cd still with u, then open nero (not the wizard but the other one. then in the recorder menu, select image recorder. after this, select to burn cd and it'll prompt u for a location where u want to store the image. let it complete and u r done, it creates an iso image for u which is an exact copy of the cd that u used. so if ur original cd was bootable, then u r good to go. then when u want to burn this image onto a cd, select recorder and select ur actual cd burner in the list. then select burn image and select the image location and burn it onto ur disk.

if ur original disk wasn't bootable then in nero there is an option to make a bootable disk but as i said before it might not work correctly. hope it helps.