I have both Visual Studio 2010 and 2012 installed on the same machine. When I load a project I get the message "Loading toolbar content from package 'Microsoft.VisualStudio.IDE.ToolbarControlsInstaller.ToolbarInstallerPackage' {2C2988B35-07DA-45F1-96A3-BE55D91C8D7A}" in VS 2010's status bar and it just sits there until it's done. To fix this problem I've gone through the registry and removed all instances of the GUID: {2C2988B35-07DA-45F1-96A3-BE55D91C8D7A}. This fixes the loading issue; however, I don't have the Infragistics toolbox with the controls.
Have you run the Toolbox Utility?
I did run it as I was missing the toolbox items for Infragistics and that is when this loading issue started. I noticed the utility also installed toolbox entries for older versions still installed (10.x) so I went and uninstalled all previous versions except (2011.1 and 2011.2) and removed all WPF (included 2011.1 and 2011.2) and the issue persisted.
I've attached a log file by running devenv.exe /log c:\temp\ideLog.txt (ideLog.txt)
I then re-ran the "Create Visual Studio Toolbar Tab for CLR4.0"; but, that didn't seem to fix it either. (attached the log ideLog2.txt)
In a case like this it looks you will have to drag the dll's that you neeed into the toolbox manually from the bin folder. Unless you want to run the installation again. But since you have already tried it a couple of times I think your best option is to bring them in yourself.
I had WinForms CLR 2.0 and 4.0 toolbox and that took 3 minutes to load from the point the status showed the loading message. I went into the registry and removed all the keys: {2C2988B35-07DA-45F1-96A3-BE55D91C8D7A}
When I loaded my VS solution I was surprised I still had the toolbox for CLR 4.0; but, not 2.0
When I need the CLR 2.0 controls I'll manually add the ones I use and see if loading slows at loading the toolboxes again.
Noticed that this issue does not present itself if Visual Studio is running "As Administrator". Today, I opened a solution by double clicking the .sln file and then I opened the same solution with VS that was already running in Administrator mode and it opened no problem while I waited for the other instance to finish loading the toolbox.
Same GUID.