Windows: How to check if an executable is 32-bit or 64-bit?

1. Open the .exe file in a text editor. Don't use the build-in notepad as it does not handle large files very well. I strongly recommend using Notepad++.

2. Search for the first occurrence of "PE"

3. Check the next printable character after "PE".
For x86, it should be "L".
For x64, it should be "d†".


Ref:
64 bit - How to check if a binary is 32 or 64 bit on Windows? - Super User