If you are still using Windows XP, you may wish you could moist ISO images like in Windows 7 or 8.
Correction: If you are using Windows 7, Windows Vista or are still too stubborn to move from Windows XP, Microsoft has released a tool that lets you mount ISO files like you can on Windows 8. Windows 7 does not have the capability to mount ISOs, that came with Windows 8 - The closest that 7 has is the ability to burn ISOs to disc without any extra software.
Microsoft did not release this tool for "die-hard XP users" (although you are clearly saying this so you can hold on to some fake belief that MS still want to support XP), they released it for all Windows versions that it would be compatible with and that will currently still be in use. Did you just read the title, get to the bit where it said "Windows XP" and just stop there rather than also reading the bit that states "Vista, and 7"?