When SPD 2010 was released, the industry was in the middle of a transition from 32-bit (x86) to 64-bit (x64) computing. The is essential for users running 64-bit versions of Microsoft Office.
If you need help migrating an old SPD 2010 workflow to Power Automate or SharePoint Online, I provide a full technical guide for that instead. microsoft+sharepoint+designer+2010+64bit+portable
If you need to use SharePoint Designer 2010 on a 64-bit system, the best practice is to use the official free installer provided by Microsoft: Microsoft Download Center File Name SharePointDesigner.exe (approx. 279 MB) System Compatibility Windows 7, Windows Server 2008 R2, and newer Critical Requirement When SPD 2010 was released, the industry was