QuickBooks Connection Diagnostic Tool is a well-designed tool by Intuit to troubleshoot networking and multiple user errors that usually occurs while the user tries to open the company file. The major errors that the tool can identify are H202, H505, or 6000 error series. The QuickBooks Connection Diagnostic Tool limits functioning only to specific versions. For the computers running Microsoft Windows Vista or XP with QuickBooks 2010, 2009, or 2008 or Enterprise Solutions 10.0, 9.0, or 8.0 it doesn’t function. Hence ensure the computer version before downloading this tool. For the more information about the tool, you can contact QuickBooks Help +1-877-249-9444.