I believe I may have already posted a much longer explanation of this , but its driving me spare!!!

I have several pieces of code that click buttons thru sendmessage commands, all the code works fine in Windows 7!
But I put the app on WindowsXP and only some of the buttons will work, can anyone give me any ideas as to whats going on?

I have seen it suggested out there that maybe the handles arent correct etc. but then why would the button code work on one version of windows and not on another?

By the way the buttons being clicked are on itunes, which is the same version across all platforms. Plus i have updated everything i can think of within the OS AND Visual Studio.

Can anyone give me some idea where to hunt down the problem???

4 Years
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Last Post by Begginnerdev

Have you tried going into your application settings and going to the Compile tab > Advanced Compile Options (button at bottom), and changing Target CPU to (x86).

It could be that your Windows 7 version is 64-bit and your XP version is only 32-bit. I am not too sure if that is the issue, but it is worth a try.


I looked at doing this but my visual studio version is express and doesnt have the cpu target option. Aside from that I checked the machines im running on and the windows 7 version is not 64 bit.
it was suggested to look at how i was using the "user32.dll" , how i was importing it. I had been using 'auto function lib' to get at the commands i wanted. i then tried using all 'dllimport' commands for what i needed but its the same result...some buttons will work on xp and others wont, win7 everything works fine...
thank you for your suggestion though, i appreciate any ideas on where to look for this weird problem


Have you made sure the the dll import points to the right dll in Windows XP?

Edited by Begginnerdev: n/a

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