Hi, Happy new year! I try to wrap some API methods using NativeBoost to access Win32 Registry and broaden the Pharo support for Windows. Currently I'm already able to - create registry keys (RegCreateKeyA API) - open registry keys (RegOpenKeyExA API) - delete registry keys (RegDeleteKeyA API) - close registry key handles (RegCloseKey API) Now I additionally want to query some keys using the "RegQueryValueExA" API (http://msdn.microsoft.com/en-us/library/windows/desktop/ms724911%28v=vs.85%2...). As I tried an example in an elder Smalltalk/MT first (see attached) I know it is working from the Win32 API side. My NativeBoost definition in Pharo for wrapping the function looks like this (similar to MSDN): regQueryValueExA: hKey with: lpValueName with: lpReserved with: lpType with: lpData with: lpcbData <primitive: 'primitiveNativeCall' module: 'NativeBoostPlugin'> ^ self nbCall: #(LONG RegQueryValueExA( HKEY hKey, LPCTSTR lpValueName, LPDWORD lpReserved, LPDWORD lpType, LPBYTE lpData, LPDWORD lpcbData)) module: #advapi32 But when I call it I get a "Generic error" thrown by NB and independent how hard I try I can not get this call to work in NativeBoost. I checked all arguments, checked the type definitions (pool WinTypes which is similar to NBWinTypes), played with options, ... but was not able to find out what I'm doing wrong in Pharo. Meanwhile after investing several days of my spare time it looks like I cant "see the wood because of all the trees". I would really appreciate if someone with enough knowledge of NativeBoost could have a second look to point my into the right direction. To reproduce: ============= - use a fresh Pharo4.0 Latest update: #40428 - open World menu -> Configuration Browser and load "OSWindows" project - go to class WinRegistry - there is the NativeBoost API definition in method #regQueryValueExA:with:with:with:with:with: - and a method #example2 that calls this in a similar way as in my Smalltalk/MT example (if you try this example you get the "Generic error") Many thanks in advance! Bye T.