Good call on R2. That was a pre-coffee moment for sure.
You could disable the check for SIM pre-reqs:
- Add key HKEY_LOCAL_MACHINE\SOFTWARE\Altiris\AIM to the registry.
- Create a DWord named IgnoreInstallPrerequisites; set the value to 1.
- Add key HKEY_LOCAL_MACHINE\SOFTWARE\Altiris\AIM\InstallReadinessCheck\ to the registry.
- Create a DWord named EnableNextButton and set the value to 1.
Does this get you anywhere? If it's actually seeing some sort of issue in the environment, this won't solve the problem. I would verify each of the requirements independently before running the install to make sure they're met (OS, browser version, IIS configuration, etc).