Why won't Office 2011 install on Snow Leopard? I'm trying to install Office on my mother-in-law's MacBook.  The installer fails every time with:

12/28/12 12:26:42 PM    installd[1798]  PackageKit: Install Failed: PKG: pre-install scripts for "com.microsoft.office.all.quit.pkg.14.2.0"
Error Domain=PKInstallErrorDomain Code=112 UserInfo=0x103b1da10 "An error occurred while running scripts from the package “Office Installer”." {
    NSFilePath = "./preinstall";
    NSLocalizedDescription = "An error occurred while running scripts from the package \U201cOffice Installer\U201d.";
    NSURL = "#Office2011_all_quit_14.2.0.pkg -- file://localhost/Volumes/Microsoft%20Office%202011/Office%20Installer.pkg";
    PKInstallPackageIdentifier = "com.microsoft.office.all.quit.pkg.14.2.0";
}

Outside of the timestamp, installd process ID and userinfo number, it's always the same message.

Here's the hardware overview from system_profiler:

  Model Name: MacBook
  Model Identifier: MacBook2,1
  Processor Name: Intel Core 2 Duo
  Processor Speed: 2 GHz
  Number Of Processors: 1
  Total Number Of Cores: 2
  L2 Cache: 4 MB
  Memory: 2 GB
  Bus Speed: 667 MHz
  Boot ROM Version: MB21.00A5.B07
  SMC Version (system): 1.13f3


I've updated all of the software using Software Update and I've repaired permissions on the hard drive.
I tried to answer this the day after I posted the question, but my in-law's Internet connection wasn't being cooperative.

I was only able to install Office after we wiped the machine and reinstalled Snow Leopard.  I have no idea what the actual problem was.  The machine was really slow anyway and now it's running like new.

I guess the old rule about Microsoft Windows extends to MS Office for Mac:  format and reinstall.  :(