Is it possible to boot a desktop computer without a hard drive in it?
How, I want to boot and get into the window on Dell Dimension 9200
You can boot without a hard drive, but you need a source from which to load Windows. Either from optical disk, USB or hard drive. You may want to check out UBCD4Win.
http://www.ubcd4win.com/
Does the computer not have a hard disk?
I have got the bootable USB, but is it even i have boot the Dell Dimension 9200, it will not go to the window, if that is the case, then what are the other option and add on i need to prepare in order to get into window xp
You need to purchase an internal hard drive and install Windows. There are no bootable copies of Windows XP. If you want something to just boot to, you'd need to run a Live distro of Linux.