I'm having issues with my BootCamp installation of Win 7 Ultimate and want to troubleshoot it using a USB Win 7 boot disk. I created the USB disk in yet another Windows system in Parallels Desktop, using an ISO of my Windows 7 DVD and the USB/DVD Download tool available from Microsoft. When I reboot the computer, the drive shows up in rEFInd, but if I try to boot from it it just loads my problematic Windows installation (with Boot Camp as the C: drive). Any ideas what I should try next?
You have not provided enough information to precisely answer your question. Therefore, I will try to cover all the bases. Older Macs can not boot the Windows installer from a USB port. Generally if your Mac was shipped with an optical drive, then your Mac is one of the older models. Another way to tell, would be to try and create the USB installer using the Boot Camp Assistant application. If you can not, then the application knows you have such a model. You may read, elsewhere, that it is possible to edit a
info.plist file to fool the Boot Camp Assistant into allowing you to create the USB Windows installer. Just because you can succeed, does not automatically mean your Mac will be able to boot from USB drive.
Again, just because rEFInd detects your USB Windows installer, does not mean your Mac can boot from the device. The tool rEFInd is a boot manager, not a boot loader. It can only override the default boot partition or device setting. The Mac firmware still preforms the operation of booting from a particular partition or device.
I believe the Windows USB installer created, using the tools provided by Microsoft, produces a installer that will not work on any Mac. I believe this to be true, regardless of the year the Mac was made. Also, for the newer Macs, the "Boot Camp Support Software" is suppose to be transferred to the USB drive before installing Windows. The allows the Windows installer the choice of substituting software, such as drivers provided by Apple and other venders, during the installation process.
As for where to go next? This depends on the model/year of your Mac and the version of OS X you have installed.