The Win32 API call RegisterTypeLib() is used to create the registry keys necessary to register a type library.
Unfortunatly, on Windows XP, it tries to write those registry key entries to
HKEY_CLASSES_ROOT\TypeLib
rather than
HKEY_CURRENT_USER\Software\Classes\TypeLib
Meaning that a standard user will not be able to run an ActiveX.
In May 2008 Microsoft released a hotfix for Vista to correct this issue - but the problem remains on Windows XP.
What's a standard-user friendly developer to do?
Answer 1
Use the API call that is designed for it:
RegisterTypeLibraryForUser()
Answer 2
If you can't fix it, hack it:
//begin hack
HKEY key;
RegOpenKeyW(HKEY_CURRENT_USER, @"Software\Classes", out key);
RegOverridePredefKey(HKEY_CLASSES_ROOT, key);
//do original work
RegisterTypeLibrary(...)
//stop hacking
RegOverridePredefKey(HKEY_CLASSES_ROOT, null);
RegCloseKey(key);