download core.dll:https://www.dll-files.com/core.dll.html
- Open the zip-file you downloaded from DLL-files.com.
- After extracting your zip-file, place the extracted DLL-file in the directory of the program that is requesting the file. Make sure to use a 32bit DLL-file for a 32bit program, and a 64bit DLL-file for a 64bit program. Failure to do so will likely result in a 0xc000007b error.