DD> Can anyone recommend any freeware/shareware debugging tools suitable for 
DD> simple patching of a mis-behaving executable for which I have no source?  I 

I wrote a program "zap" to do that.  There's not a great deal to
that though, probably you really mean is there a free debugger.  In which
case, EMX 0.9c has one, but I've never used it.

DD> The particular case in point is the DeScribe Frequent Flyer
"Upgrade" to 
DD> DeScribe Voyager, which refuses to operate in my desired environment.  As 
DD> DeScribe is in liquidation no support is coming from them and we are on our 
DD> own.  What I forsee as my method of correcting this problem is to load the 
DD> program with a debugging trace record in the environment in which it works 
DD> and then do so again where it fails.  This should enable me to locate the 

Sounds like you've got one "machine" where it fails, and one
where it "works", in which case, this sounds fair.

DD> faulty test which is forcing an abnormal exit and allow me to determine 
DD> which instructions to NOP out to avoid the incorrect exit.

Sounds like the most viable approach, but I wouldn't want to bet money that
NOPs will circumvent what sounds like a bug.  Bugs normally aren't so easy
to fix!!!  Dongle protection is, but not bugs.

DD> I have asked here earlier if anyone had solved this problem and received no 
DD> response, so I assume its up to me to take this on myself.  

I checked, and yes, you did send a previous message, and it did get
through, so yes, you have drawn the correct conclusion.  :-)  I've never
even heard of the application before, and I'm not in the least surprised
that no-one has patched it.

DD> If anyone has a 
DD> better approach or other suggestions I will be happy to hear them.

No, you're doing the best you can.  You should probably consider changing
to a different product though, one that has support.  BFN.  Paul. 
@EOT:

---