how in is possible to install an operating system on a operating system ( instalingl xp on windows 7) that not possibly directley..
however, its possible by using virtual machines
microsoft's virtual pc *******free
(dont download xp mode on this download page, its for different purpose.. just dowdload virtual pc....)https://www.microsoft.com/windows/virtual-pc/download.aspx
virtual box from oracle****freehttps://www.virtualbox.org/
vmware player https://www.vmware.com/products/player/
all of them have nice help docs, but if you need help, always welcome....