HTC Sensation fastboot unknown device I experience problems trying to root my HTC Sensation.
I turned USB Debugging ON, checked that Fast boot is turned ON in Settings &gt; Power section and connected phone to PC.

My device was recognized successfully

Also it was shown in adb list
C:\sdk\platform-tools&gt;adb.exe devices
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
List of devices attached
HT15LVXXXXXX    device

Now i took out my battery, inserted that back, pushed and hold Power button and Volume Down and voila, i am in HBOOT.
I pressed Power button once, choosing FASTBOOT

My phone connected to Windows, but this time device was not recognized.

I tried to add drivers for that device manually, but it failed

I even tried to add %MyHTC%=HTCAND32.Dev, USB\UNKNOWN to androidusb.inf and then add driver manually, but device was not working anyway and fastboot devices command returned empty list.
I tried same operations on my Mac using fastboot-mac for that and i got same result as on Windows - device is not recognized in fastboot mode.
Any ideas?
you need to unlock thebootloader first before doing anything... the screen shot shows that your phone is still locked 
you can do that on HTCDEV site