This demo uses the freeware Synapse lib internet code
to get the new exe from your website.....you can use any code
you wish instead... just so long as it can get a file and place
it into a stream.

Just place any delphi exe that has been compiled with the
ExeMod.pas unit included onto your website and then type the
url into the edit box on the form... when you click the 
[update exe from url below] button the program will grab
the new exe from your site and place it into a memstream
and swap the new version for the old version... this may take
a few moments so be patient... the button will stay depressed
while the update is in progress..

I included a button to update the exe from a local file... this is
for testing purposes and works identically to the url method except
the new exe is on your local hd.  Just select the exe you wish to swap
in in place of the original and it will exchange and come up running
very quickly :-)

Appologies for the crudity of this demo... I was in a hurry.
also I did not get to test the url method as I have no web space
where I can place an exe to test with... Geocities does not allow
for direct lnking to files :-(  but it should work OK...