For HTTP GET 101, try the source code at http-get. If you want something better (that parses re-directs, deals with proxies, etc), then you can either use the Windows-only Internet API (see MSDN), or an opensource library like GNet or JigSaw.

You cannot secure the client. The user who wants to patch the client-side files, would simply modify the checksum algorithm on the client program to return the data that the server wants to see, then actually use the modified data.

hi hplus,

i have a quick thing i would like to get your opinion on. do you think i should hard-code the version number into the client? or, should the client get this from a file? if i do it the first way, this means i must always send a new .exe file with each update, regardless if i actually changed the exe or not (although to be honest, i dont see this happening too frequently. most updated probably will change the .exe). also, it would make connections slightly faster since no file i/o is needed. another advantage is that the user cant screw up and delete his .cfg file and therefore have to re-download the game when this happends.

I would store one version number in the data directory, for the data files, and hard-code one version number in the game, for the exe. Then, you can send both to the patch server, which can decide whether to update data, update the EXE, or both.

If the user deletes files, they're on their own -- download the entire game. After all, if they screwed up the .cfg file, they might have screwed up other things, too.

Well, I've one developed, if you wanna take a look:

http://cofruben.krusher.org