Immediate error running setup.exe for IIS 7 application

We made an application for a client. The app is .NET/Silverlight 4, 开发者_开发百科running on IIS7. We also made an installer using the "Web Setup Project" template from VS2010.

On our local machines, and in our test environment, the installer always worked fine. And on the client's Dev environment, it worked fine as well. But the client then built a completely new machine to use for full UAT. When the installer ran on that machine, it immediately failed and stated:

"Installation Incomplete: The installer was interrupted before could be installed. You need to restart the installer and try again. Click Close to exit"

.NET 4 is installed, Silverlight is installed, and IIS 7.5 is installed.

That is all. No indication of what the error was, just that immediate message. Any ideas?

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One thing to check is whether the customer installed the IIS6 compatibility bits. I have a feeling this is still needed even on IIS7.x.

I'd also check the installer log if one got generated to see if anything jumps out. And it's also worth having a trawl through the server's event logs to see if anything got logged there.