How to determine whether windows programs are 32-bit or 64-bit

If VS2012 is installed, open a console window provided by VS 2012, such as VS2012 x64 Native Tools Command Prompt.

Run the following command to view the program header information:

 

gdal_1.8_rtc>dumpbin /HEADERS gdal18.dll Microsoft (R) COFF/PE Dumper Version 11.00.60610.1 Copyright (C) Microsoft Corporation.  All rights reserved.   Dump of file gdal18.dll  PE signature found  File Type: DLL  FILE HEADER VALUES             8664 machine (x64)                6 number of sections         52130233 time date stamp Tue Aug 20 13:44:19 2013                0 file pointer to symbol table                0 number of symbols               F0 size of optional header             2022 characteristics                    Executable                    Application can handle large (>2GB) addresses                    DLL gdal_1.8_rtc>dumpbin /HEADERS gdal18.dllMicrosoft (R) COFF/PE Dumper Version 11.00.60610.1Copyright (C) Microsoft Corporation.  All rights reserved.Dump of file gdal18.dllPE signature foundFile Type: DLLFILE HEADER VALUES            8664 machine (x64)               6 number of sections        52130233 time date stamp Tue Aug 20 13:44:19 2013               0 file pointer to symbol table               0 number of symbols              F0 size of optional header            2022 characteristics                   Executable                   Application can handle large (>2GB) addresses                   DLL

Have you seen x64? So this is a 64-bit dll.