I installed the Twonky Beam for Windows from the download on the Twonky website last night. On my Windows 7 Machine with IE9 the Twonky Beam Sidebar is not visible under view/sidebars menu drop down. The same thing on my Windows XP machine with IE8. The Twonky sidebar is not visible under view/sidebars menu drop down.
The funny thing is that I installed Twonky Beam for Firefox on the Windows XP machine and it works perfectly.
I have Twonky Mobile on my Android Phones and the work great beaming to Windows Media Player on Windows 7 and Windows XP.