When trying to open the Registry Explorer icon, Windows Explorer generates an error, similar to the following:
There was an internal error in one of your explorer windows. This window will be closed.
This problem occurs only on Windows XP with Registry Explorer 1.0, 1.1 or 1.2.
This problem is due to compatibility problems.
Certain pieces of code in the Windows XP shell are not backwards compatible with earlier versions.
More specifically, the IPersistFolder2 interface has been superseded by IPersistIDList, and no checks are performed for ensuring backwards compatibility.
The problem has been solved in version 1.3 of Registry Explorer.
Upgrade to this version.