Thanks to Dhirendra Yadav for posting how to set the “Enable Client Integration” property using the SharePoint 2010 OM. I’m reposting here because I had a little trouble finding his post initially. And thought it’s not a big deal to convert it, I’ve put the code into something runnable from your PowerShell command window.

Here is Mr. Yadav’s original code:

using (SPSite siteCollection = new SPSite(http://{your site url})) {
   
  //enable client integration 
  siteCollection.WebApplication.IisSettings[SPUrlZone.Default].EnableClientIntegration = true;
   
  //disable client integration 
  siteCollection.WebApplication.IisSettings[SPUrlZone.Default].EnableClientIntegration = false;

  siteCollection.WebApplication.Update();

}
 
And here is my version, converted for use via PowerShell:
  // Initiate a new assignment store so we can clean up our SP objects afterward
  $gc = Start-SPAssignment
  // get a specific Site Collection
  $s = $gc | Get-SPSite http://{your site url}
 
  // Use the IisSettings object on the WebApplication to update EnableClientIntegration
  // enable client integration
  $s.WebApplication.IisSettings[[Microsoft.SharePoint.Administration.SPUrlZone]::Default].EnableClientIntegration = $true
 
  // disable client integration
  $s.WebApplication.IisSettings[[Microsoft.SharePoint.Administration.SPUrlZone]::Default].EnableClientIntegration = $true
 
  // Make sure to call update on the Web Application
  $s.WebApplication.Update()
 
  // And dispose of the SPAssignment (i.e. the Site Collection object)
  Stop-SPAssignment –Identity $gc