Once again, the XP.iso works in a different way from the 7.iso and another.iso may work the same way as one of the said two or in a third (or nth) different way. In a nutshell, a 7.iso should work 'as is', an XP one needs to be specially crafted/modified. It can even boot operating systems directly from an ISO file stored on your hard drive. It is regularly updated by open-source community of developers and is completely safe to use on your Windows PC. The only problem with GRUB is that is it not so easy to install on a system that already has Windows installed.
Balumama Chya Navan Chang Bhala - बाळूमामाच्या नावानं चांगभलं - Episode -408 & 409 - Recap.