Couldn't connect to remote RDP machine

Couldn’t connect to remote RDP machine. After Dynamic Tunnels connection successful, I am clicking on ‘Yes’ button in the warning pop-up (which states 'Are you sure you want to launch “C:\WINDOWS\system32\mstsc.exe” /Span?)

But Instead of launching ‘Remote desktop Connection’ window, I am getting usage information pop-up. PFA.

Sytem Details: OS: Win XP SP2 Browser: IE7

Log Details: OS Name: Microsoft Windows XP Version: 5.1 Build: 2600 Type: Multiprocessor Free Primary UI language: 0x9 Short Name: WinXP Service Pack: Service Pack 2 HOTFIXES: SP2;KB888111WXPSP2;Q147222;

Let me know if you need any more details. Can anyone help me in fixing the above issue.

Thanks in advance!

That indicates, to me at least, that the MSTSC.EXE version you’re using does not support the /span argument - which I assume wouldn’t work in a Windows XP environment (because /span was introduced in Windows Vista).