Fixing ".exe has stopped working" error

I've been looking for a solution in fixing the ".exe has stopped working" error.

Youtube tutorials' not working at all (most of them are just the same copy-paste video but different narration anyway)

I'm using Windows 8.1 with 64-bit OS, if this bit is any use in solving this matter.

Help needed. Thanks...

I'm sorry if you mean that your exe worked fine, then it suddenly crashed? It can be virus invasion or others.

And do you have any backup of computer before? Since it's crucial to restore any program back to their working statues.