How to deploy Qt-dlls for windows

**niko** · 18th March 2007, 15:10

Hello,

I'm currently creating an installer using NSIS - so far it was fairly easy.
But one question: where should i install the Qt-dlls?
QtCore4.dll, QtGui4.dll etc...
Installing them in the application folder means every qt application has to install his own version of them (WengoPhone does it like that).

Wouldn't it make more sense to install them in c:/windows/system32?

Would it cause troubles when any other installer updates them?

thanks,
niko

**jpn** · 18th March 2007, 16:09

Originally Posted by niko

But one question: where should i install the Qt-dlls?
QtCore4.dll, QtGui4.dll etc...
Installing them in the application folder means every qt application has to install his own version of them (WengoPhone does it like that).

Yes, I think that's quite common way do deploy the libs on Windows.

Wouldn't it make more sense to install them in c:/windows/system32?

Would it cause troubles when any other installer updates them?

The problem is that any other installation overwriting them with older versions could even prevent your application from launching. For example, let's say your application depends on new functions introduced in Qt 4.2 and some other installer overwrites the dll's with 4.1 ones.

**niko** · 18th March 2007, 16:30

Originally Posted by jpn

The problem is that any other installation overwriting them with older versions could even prevent your application from launching. For example, let's say your application depends on new functions introduced in Qt 4.2 and some other installer overwrites the dll's with 4.1 ones.

and installers actually do this? this is crazy!

ok, so i'll pack them into my installation folder - no problem for me

thanks!
niko

**jpn** · 18th March 2007, 16:48

Originally Posted by niko

and installers actually do this? this is crazy!

Well, depending on the installer, usually the user is prompted with a question like "A newer version of this file exists, blaablaa?" But you never can be sure what people answer to them, if they even bother to read the popups..