Even more peculiar is have the E in 'ecake' disappears, what a mystery! :icon_lol:

I think first you need to simplify, so as that you can clearly follow and read it. For instance: that whole if(hexstring[i+2]==10 through 15) and then ending it with a redundantly unnecessary else...

The only times it should ever be used are of the most rarest situations.
So don't get any ideals about using in substitution of well planned logic.

Don't use goto, try a function. You already have a switch in an if statement, don't make it any more complex.

Avoid fflush() and look into a replacement of scanf()

conio.h isn't used, and should never be.
Macros used like that are dangerous.
It's: int main() { return(0); }

You mean those format things: http://www.cplusplus.com/reference/clibrary/cstdio/printf/

It doesn't work because you're using nonstandard code written for ancient compilers.
conio.h should be removed from your code.
main() by standard requires a return value(except in very rare...

What is with all the Turbo C++ references?!! That compiler is a non-standard relic from another millennial! It's useless!

marco93 is just a bot that's managed to strangely survive for so long.

Google, "rot13" That's as easy as it gets... well, actually using bit-operations are easier by a few lines less typed.