I have just spent an hour of my life—one that I will never get back—trying to figure out why I couldn't install any software from .msi files on one of my Windows 7 machines. Every time I tried, I would get a message that the installer "could not find the file specified."

I'll spare you all the steps I went through to figure out why this was happening, and get to the punchline:

Yeah, you see, the SYSTEM account needs full control over any file you're trying to install on Windows. Here's how it should look:

So, if you're a security-conscious individual who's locked down his PC thoroughly, and you can't seem to install anything on Windows anymore, check the permissions on the folder containing the .msi file.

As we say in programming: herp-a-derp.