Errors when Installing DirSync.exe

I ran across two different errors with DirSync today.  The first had to do with the fact that I had DirSync on a computer previously and then re-installed it.  Because of this, I received this error:

System.Management.Automation.CmdletInvocationException: Access denied  —> System.Management.ManagementException: Access denied
   at System.Management.ManagementException.ThrowWithExtendedInfo(ManagementStatus errorCode)
   at System.Management.ManagementObjectCollection.ManagementObjectEnumerator.MoveNext()
   at Microsoft.Online.DirSync.Common.MiisAction.GetTargetMA()
   at Microsoft.Online.DirSync.Common.PrerequisiteChecks.ThrowIfSyncInProgress()
   at Microsoft.Online.Coexistence.PS.Config.SetCoexistenceConfiguration.VerifyMachinePreRequisites()
   at Microsoft.Online.Coexistence.PS.Config.SetCoexistenceConfiguration.BeginProcessing()
   at System.Management.Automation.Cmdlet.DoBeginProcessing()
   at System.Management.Automation.CommandProcessorBase.DoBegin()
   — End of inner exception stack trace —
   at System.Management.Automation.Runspaces.PipelineBase.Invoke(IEnumerable input)
   at Microsoft.Online.DirSync.PowerShellAdapter.PowerShellCommand.ExecuteCommand(Command command, Boolean refreshPath)

Looking a little deeper, it turns out that DirSync install will create a user account and then add it to other created local groups.  This is all very similar to how SharePoint installs because both DirSync and SharePoint use MIIS. Because I had already installed DirSync at some point in the past, the account existed, but I'm guessing the password was out of whack.  Since I wasn't sure how to reset the password (and didn't want to spend the time to figure it out), I defaulted to uninstalling everything, deleting that user, rebooting and re-installing. Done.

But it didn't end there.  I was attempting to install a secondary DirSync machine as a cold standby, but was getting an error when attempting to configure it:

System.Management.ManagementException: Generic failure
   at System.Management.ManagementException.ThrowWithExtendedInfo(ManagementStatus errorCode)
   at System.Management.ManagementObjectCollection.ManagementObjectEnumerator.MoveNext()
   at Microsoft.Online.DirSync.Common.MiisAction.GetTargetMA()
   at Microsoft.Online.DirSync.Common.MiisAction.IsSyncInProgress()
   at Microsoft.Online.DirSync.Common.PrerequisiteChecks.ThrowIfSyncInProgress()
   at Microsoft.Online.DirSync.UI.IntroductionWizardPage.PrerequisiteValidation()
   at Microsoft.Online.DirSync.UI.IntroductionWizardPage.OnLoad(EventArgs e)
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

This means that the DirSync tool was not smart enough to tell you that you were installing it on a SharePoint server (which I didn't realize I was doing) with the ForeFront services already installed.  When you attempt to do this, you will overwrite your SharePoint ForeFront settings with the account mentioned above and then the two will fight over the service.  Obviously, this is bad.  I hadn't really done much research on some of the best practices around DirSync so its a bit of shame on me, but I also didn't find answers to these errors on the web when I google/binged them, so I'm making a mental blog note for others.