Save docrypt.exe wherever you like (e.g. any drive, flash drive, etc.)
Clicking docrypt.exe installs & runs program.
Docrypt shows you a link where Oracle Corp. (Java's owner) enables free Java download.
After installing Java, click docryt.exe.
If still not working, the following will build a log file with (hopefully) helpful debug info.
Open command prompt (in same folder as docrypt.exe)
and type: docrypt.exe --l4j-debug-all