I seem to get this a lot in mIRC, and I know that mIRC is a large cause of this error coming up in Windows, something about hogging heap resources.
"The second SharedSection value (3072) controls the size of the desktop heap (used for Windows objects). This static value is used to prevent ill- behaved applications from consuming too many resources. Because the desktop heap is mapped into each process' address space, this value should not be set to an arbitrarily high value (as it would decrease performance), but should only be increased sufficiently to allow all the desired applications to run. For more information about the parameters of the SharedSection key, click the following article number to view the article in the Microsoft Knowledge Base:
184802 PRB: User32.dll or Kernel32.dll fails to initialize"
Is what I found... and yeh, "ill-behaved applications" makes me lol a bit, but it's still an annoying issue.
I'm regularly in around 75 channels across 6 networks with 10 @windows and various amounts of PM windows, usually around 3. Then there's the close to 25 other open windows I have besides mIRC (browsers, cmd windows, folders, notepad's, other instances of mIRC, trillian, etc) ... In any case, this adds up too fast and mIRC just causes a lot of issues, most likely due to handling how windows are created poorly
I wouldn't begin to know how to fix such a thing, but it would be great if it was fixable because I'd rather not have to go registry hacking to fix something mIRC is breaking on a continual basis. This also means that other Windows windows can't be created or opened when this starts happening in mIRC, also prevents the right click menu from working. Really... there has to be a better solution to how mIRC handles the heap so that it doesn't make everything shit bricks.