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Posted 12 Oct 2011

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Using a 32-bit COM Object from a 64-bit Application

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4.67/5 (7 votes)
16 Oct 2011CPOL
How to edit the Registry to allow 64-bit applications to access 32-bit COM objects.

I have an application that I wanted to be 64-bit for some work being done for a third party DLL, but I have a 32-bit DLL that I need to use in the same application.

By modifying the Registry, you can allow a 64-bit app to use a 32-bit COM object.

  1. Locate your COM object GUID under HKey_Classes_Root/Wow6432Node/CLSID.
  2. Once located, add a new REG_SZ (string) value. The name should be AppID and the data should be the same COM object GUID you have just searched for.
  3. Add a new key under HKey_Classes_Root/Wow6432Node/AppID. The new key should be called the same as the COM object GUID.
  4. Under the new key you just added, add a new REG_SZ (string) value, and call it DllSurrogate. Leave the value empty.
  5. Create a new key under HKey_Local_Machine/Software/Classes/AppID, if it doesn't already exist. Again, the new key should be called the same as the COM object's GUID. No values are necessary to be added under this key.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Software Developer State of Arkansas & Zycron
United States United States
Bryan Lee learned to code on a RadioShack Color computer II.

Comments and Discussions

QuestionShame on you! Pin
Valya-S7-Sep-17 13:23
MemberValya-S7-Sep-17 13:23 
QuestionCan't make it work Pin
Member 1033089114-Oct-13 7:59
MemberMember 1033089114-Oct-13 7:59 
QuestionNice trick Pin
skydger7-Oct-13 1:56
Memberskydger7-Oct-13 1:56 
QuestionAwesome tip! Pin
zeroth100010-Sep-13 13:10
Memberzeroth100010-Sep-13 13:10 
QuestionWhy it's become much slower when use in 64bit than when in 32bit Pin
Sophy Huang4-Aug-13 21:59
MemberSophy Huang4-Aug-13 21:59 
QuestionIt works on my 64bit application when access 32it improc server. Pin
Sophy Huang10-Jul-13 21:53
MemberSophy Huang10-Jul-13 21:53 
QuestionEvents Pin
Member 8890102-Apr-13 5:47
MemberMember 8890102-Apr-13 5:47 
QuestionI have issue. Pin
paragpatel3114-Dec-12 0:47
Memberparagpatel3114-Dec-12 0:47 
AnswerRe: I have issue. Pin
BryanLeeWilliams14-Dec-12 4:31
MemberBryanLeeWilliams14-Dec-12 4:31 
GeneralYou're welcome and thanks for the 5! Pin
ARBebopKid8-Dec-11 3:30
MemberARBebopKid8-Dec-11 3:30 
GeneralReason for my vote of 5 Works fine under Win7-x64 and saves ... Pin
MrRexx8-Dec-11 2:02
MemberMrRexx8-Dec-11 2:02 

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