As you are well aware, all BizTalk programs must reside in the GAC. Many of use the “shell extension” to drag and drop programs to the GAC. But BEWARE, this tool is gone in .NET 4.0.

See here for the Microsoft Official Statement:

Former link was moved by MSDN:

“Beginning with the .NET Framework version 4, the Assembly Cache Viewer (Shfusion.dll) is obsolete and has been removed. Use Gacutil.exe (Global Assembly Cache Tool) to view and manipulate the global assembly cache.”

For a good explanation, see the answer to this popular question on Stack Overflow (GAC).

We recently learned that when you have MSMQ clustered, you cannot go to the normal “Manage Computer” to manage the queue. Instead, you have to run a special utility:

MMCV –s YourMSMQClusterName

The above utility can be downloaded from Microsoft.