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 > Power** section and connected phone to PC. My device was recognized successfully Also it was shown in adb list C:\sdk\platform-tools>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?