I am still in the trial period of using mIRC so please let me know if this is my issue.

I recently loaded mIRC and Invision on my Vista box. When I access a link from a site such as packetnews, I get the following error: Windows cannot find 'irc://.....'. Make sure you typed the name correctly, and then try again.

I saw a post for this before, but was unable to find it again. Maybe it was on the Invision site.
I am running 6.21 with Invision 3515b

Turn on DDE in mIRC's options -- Alt-O > Other > DDE > Check the first box.

I've downloaded, installed (and registered ) mIRC 6.21, I've checked the DDE Box (was already checked) but it doesn't do the trick.... I've also tried the associate extension/protocol (through Control Panel) but no success there either... Any other thoughts or should I just wait for the next version, and if yes, when will that be?

I'm seeing the same issue here under Vista with Internet explorer. The strange thing is that Firefox handles mIRC's irc:// links fine under Vista with no changes. I have not been able to pinpoint why Explorer is having such a hard time yet. If anyone figures out how to set up working irc:// links under Vista for Internet Explorer please let me know.

I have now found this really useful link that gives a good explanation about UAC, elevation, automatic detection and manifests.

http://www.helpware.net/VistaCompat.htm

This helps explain the registring of files in Vista.

From my best guess is that this is not happening.

Thanks, it looks like you may be right. I narrowed the issue down to a DDE communication problem. It seems that Internet Explorer is unable to contact mIRC via DDE, though I'm not sure why since Firefox is doing so without a problem.

To see whether this was an elevation issue, I disabled UAC and restarted Vista and tested again. This time Internet Explorer was able to contact mIRC via DDE and it all worked fine.

I turned UAC back on again and restarted Vista, and tested again and the problem was back. I then gave mIRC Administrator privileges, digitally signed it, and tested again. The problem was still there.

I then ran Internet Explorer as Adminstrator (right-click on Internet Explorer icon, select Run As Administrator) and tested again, and this time it worked fine with a plain mIRC 6.21.

It's possible this could be an Internet Explorer/Vista bug, or that mIRC isn't doing something right. I'll be looking into it further.

You may need to make sure the Firefox builds you are testing with are not running under a shim to disable UAC. I think the versions 2.0 thru 2.0.0.2 have the shim applied. Avoiding these Firefox versions will show "true" Vista behaviour. Those particular versions are all regarded as NOT compatible with Vista. 2.0.0.3 should mark the first official Firefox build compatible with Vista.

Thanks I was testing with latest trunk release of Firefox on a clean Vista install.

Unfortunately I have not been able to resolve this issue. My guess is that it is an Internet Explorer/Vista security limitation which prevents Internet Explorer from using DDE to communciate with external applications. I tested this with custom:// protocols linked to other software and the same DDE issue occurred.

For now I have removed DDE support for irc:// links under Vista. This means that irc:// links under Vista will still launch mIRC correctly, however they will launch a new mIRC each time you click an irc:// link.

Could you not add a check at startup (before the mIRC window is created) to see if another instance of mIRC is running, and if so tell that copy to connect to the server using SendMessage() ?

I implemented this method earlier today :-) I don't yet know how stable and consistent it is under all versions of Windows however it seems promising and is working with Internet Explorer and Firefox under 98/XP/Vista so far...

Great.

I doubt I'll be making the move to vista for a good while but it's nice to know one of the features I use heavily will be working when I do

So to implement this fix, what steps need to be taken or do you have this in a new release?

Apparently with Windows Vista DDE is no longer used as seen by this link: http://windowshelp.microsoft.com/Windows/en-US/Help/ed09fe66-e6ef-4f9c-8d26-ca3882d090c21033.mspx

NetDDE—For security reasons, Windows Vista does not support NetDDE. (NetDDE is disabled by default on Windows XP SP 2 and Windows Server 2003.) Regular DDE is still supported. NetDDE is a technology that allows applications that use the DDE transport to transparently exchange data over a network. The result is the application fails to exchange data over the network. To workaround, use a different networking technology, such as DCOM or Windows Communication Foundation. For more information about NetDDE, see http://support.microsoft.com/default.aspx?scid=kb;en-us;125703.

It will be in the next version as (I'm assuming) it's part of the EXE's coding that will be changed.

I would recommend using an OPC or DCOM call.
http://blog.matrikonopc.com/index.php/2006/07/

Yes, that's one way to do it, unfortunately it seems like overkill for a feature that's meant to be so simple... and that's apart from the fact that whatever I implement would have to work on all versions of windows from Windows95 onwards :-)