There's a lot of good portable stuff out there, and in my mind a support guy's best friend is some freeware software that doesn't leave a footprint. Even better for a support guy is stuff that doesn't leave a footprint, and helps to emulate hardware that may or may not even exist on the system in need of your attention! Step up Virtual CD-ROM Control Panel... your moment has arrived!
If you need to have an ISO mounted on a PC but don't want to fiddle with DaemonTools (which I think has spyware on it now or something?), or something else that edits the registry, then look no further than VCDROM - it's lightweight (30k), portable, and can even run from the network!
I've added it to my list of "must-have" portable applications for support tools, and I really use it extensively!
Check out my comprehensive (i.e. work-in-progress) portable-applications list here.
And try these links for more on this particular application;