Not all software that works on Windows XP/Vista will work on Windows 7. Mounting ISO files can be difficult if you’ve been using Daemon Tools to do it so far. There is an updated version of Daemon tool available but it is not official. You need to search bittorrent for with.
Currently we have found two utilities that support windows 7.
http://www.poweriso.com/download.htm
and
http://www.winmount.com