I mount a lot of ISO images at work and at home instead of burning them. My usual preferred tool is Daemon Tools. Unfortunately they’ve no interest in Windows 7 while it’s a beta. I went to Virtual CloneDrive instead. A reboot after the install seemed to sort it out. I’ve just mounted my Office ISO and it’s installing. I haven’t used the Virtual CloneDrive ISO mount utility in years but it works well on Win7.
BTW, the ALP mouse driver for my Vaio causes mayhem. 3 EXE’s don’t have signatures and need to be approved when I log in. One of them leaves trash on the desktop after a graphics glitch. A restore point was reloaded to unload that mess.