I recently upgraded my laptop to Windows 7 and my development desktop to Windows Server 2008 R2. While I was setting up my development environment, I ran into an issue where drag and drop in Component Services would not work on either machine. Normally I would just create my COM+ Application and then drag the DLLs into the components folder to have them registered, but this was not working on either machine.
I then tried to run some setup SQL scripts by dragging the .sql files into SQL Server Management Studio. Again nothing happened when I dragged the file over SQL Server Management Studio and let go of my mouse button.
Eventually I was able to track it down to User Account Control (UAC). I had decided to try and leave User Account Control enabled on both of these machines and up to this point I had not had many problems and everything was working as expected. But after turning User Account Control off (and rebooting), I was able to drag and drop in Component Services and SQL Server Management Studio again.
To be honest, with Windows Vista and Windows Server 2008, I immediately turned off User Access Control since it was too interfering, so I am not sure if drag and drop in these applications is a problem too. With Windows 7 and Windows Server 2008 R2 I was going to give UAC a try and leave it enabled. Maybe there is another way to enable drag and drop in these applications and still have User Account Control enabled, but at this point I have not been able to find it.
UPDATE (2010-06-21): Eric Murriguez found the solution to this problem of Windows 7 User Account Control not allowing drag and drop. There is a Local Security Policy called User Account Control: Run all administrators in Admin Approval Mode which controls this. Setting this to “Disabled” effectively means that Admin Approval Mode is no longer required for members of the local Administrators group… effectively disabling UAC entirely for those users. Which is about the same as turning off UAC entirely but still this setting allows you to control it just for administrators. The setting is found under: Security Settings > Local Policies > Security Options.