When I test my setup.exe file I get the following error message: This program cannot be installed on Windows NT Version 5.1.2600 Service Pack 1 or later.
Why is this happening, I am running Windows 8 Dev Preview too. Could that have anything to do with it?
Sounds like you've got an OnlyBelowVersion directive in your [Setup] section that is limiting it.
From the InnoSetup documentation:
[Setup]: OnlyBelowVersion
Format: a.bb,c.dd, where a.bb is the Windows version, and c.dd is the Windows NT version.
Default value: 0,0 Description:
This directive lets you specify a minimum version of Windows or Windows NT that your software will not run on. Specifying "0" for one of the versions means there is no upper version limit. Build numbers and/or service pack levels may be included in the version numbers.
From http://www.jrsoftware.org/ishelp/index.php?topic=setup_onlybelowversion
