MS Outlook freezes when trying to a attach a file. Delay sometimes can take as long as couple of minutes. Windows Explorer can also freeze at the same time.
This behaviour is most often caused by a Disconnected Network Drive or My Network Places shortcut pointing to non existing network location. Simply disconnect the old drive or delete offending shortcut and problem should be fixed.
If this doesn't help you can try deleting Temporary Internet Files and clearing Internet Explorer History.
MS Outlook 2003
MS Outlook 2007
MS Outlook 2010
If you have access to a computer enabling remote desktop is done this way:
Control Panel > System > Remote (tab) > Allow users to connect to this computer
However you could be in a situation when Remote Desktop on a computer is disabled and there is nobody who could enable it.
If you have network access (local or via VPN) to the remote computer, you can easily enable remote desktop without having physical access to the PC.
Windows XP
Windows Server 2003
You can easily remove unwanted programs from Windows Explorer "Open With" using registry.
Start > Run > regedit.exe
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\ Explorer\FileExts\[.ext]\OpenWithList
Just delete unwanted entries.
Windows XP
When opening .msg files in Outlook 2010 you my get an error "the command line argument is not valid. Verify the switch you are using".
This is most likely caused by incorrect file association.
Open any folder > Tools > Folder Options > File Types > MSG
Make sure it set to open with "Microsoft Outlook".
Click on Advanced > Open > Edit
Application used to perform action: "C:\Program Files\Microsoft Office\Office14\OUTLOOK.EXE" /f "%1" (make sure path to Outlook.exe is correct)
Use DDE: Yes
Application: Outlook
Topic: System
Windows XP
MS Outlook 2010