Configuring SharePoint 2010 to open search results in a new window requires editing the XSL that determines the search result display.
Open your search results page and edit the page. Choose Edit Web Part from the Search Core Results web part. Expand display properties and click on XSL Editor…
Copy and paste XSL into a tool like Notepadd++. Search for the section
<div class=”srch-Title3″>
Scroll down and add the attribute for target.
Copy and paste the XSL back into the window in SharePoint. Save and publish the page.
Richard Skinner 
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