Duplicate Cleaner 4 won't run on Windows XP.  Version 4 requires the Microsoft .NET Framework 4.5 which isn't supported on Windows XP.


However, Duplicate Cleaner version 3 does run on XP.  If you have a version 4 license but would like to run version 3 on Windows XP, then drop us a support ticket and we'll issue a version 3 license you can use.


You can download version 3.2.7 Pro from this page:
Duplicate Cleaner 3 Download page.