Make sure your system is WiDi compatible.
That is: it needs the right OS, right processor CPU, the right video graphics chip, the right WiFi chip, the right TV Adapter, and MOST IMPORTANTLY, the right combination of Intel's drivers for the above to make Widi functional/usable and trouble free.
The last one is what is the most critical for most users.
If you do not know these go to Intel's web site to find them:
Intel� Wireless Display — System requirements for the Intel� Wireless Display
Re-Installing Win7 will NOT solve your issue.
This is an INTEL DRIVERS' ISSUE and it is INTEL'S RESPONSIBILITY for correcting it.
Read this:
and follow that order of install, 1. WiFi drivers, 2. Video drivers, 3. WiDi drivers.
There is a Toshiba issue described there but it applies to the model indicated there.
Also read this before you start:
http://communities.intel.com/message/191071#191071
and the link in that thread and the posts there.
Use the SAME VERSION drivers described there, NOT the latest Intel driver versions, except for the Widi driver.
MAKE SURE the wifi is disabled in your notebook before you start the install process of all drivers.
FIRST, CLEAN your system as described there.
I would NOT FOLLOW the advice of the Intel reps posting in these forums as their posts are mostly useless.
More reading here:
Support for the Intel® Wireless Display
and here:
Documents & Guides for the Intel® Wireless Display
WiDi technology, as it presently stands, IS NOT A USER FRIENDLY technology, and for most users it's probably not worth the effort to make it usable and trouble free..