using com 32 bits library on 64 bits application

Question

i have a 32 com library and would like to use its functionality by a 64 bits application , i 've searched on the internet and managed to get this workaround

1. Locate your COM object GUID under the HKey_Classes_Root\Wow6432Node\CLSID\[GUID]
2. Once located add a new REG_SZ (string) Value. Name should be AppID and data should be the same COM object GUID you have just searched for
3. Add a new key under HKey_Classes_Root\Wow6432Node\AppID\
4. The new key should be called the same as the com object GUID
5. Under the new key you just added, add a new REG_SZ (string) Value, and call it DllSurrogate. Leave the value empty
6. Create a new Key under HKey_Local_Machine\Software\Classes\AppID\

but it does not work on Windows 7 64 bits , the main problem is when i do the step 6 i found the key already existed, any body knows why ? or how can i overcome it ?

the documentation here is very brief

Answer 1

So, what you need to do here is start up this 32bit COM component in its own process, ie by calling CoCreateInstance with CLSCTX_LOCAL_SERVER.

Either this will be straight forward with the existing DLL, or if not you should wrap it with your own 32bit simple COM component which supports running as a local server...

Trying to tweak the registry is a no-win game - use the Dll as it was intended and save yourself the pain.