Where can I purchase Female Thunderbolt to HDMI cable? I have a Apple Thunderbolt Display 27 which I want to use on a Windows machine with only an HDMI port. So I basically need to cable which will have female Thunderbolt port in one side and male HDMI port in other side of the cable.
There's no such thing as a female Thunderbolt to male HDMI cable.  Consequently, you cannot connect an HDMI Source to a Thunderbolt Display

DisplayPort (DP) and mini DisplayPort (mDP) can drive HDMI devices, but not the other way around.


  I also want to connect it to my Windows laptop via HDMI. I bought this
  converter, which converts the HDMI signal to DisplayPort. Everything
  plugs in just fine, but the display just does not turn on.


Source:  how do I connect an Apple Thunderbolt display to a PC?

In short, HDMI simply cannot create the "signaling" required for a DP or mDP signal.  The Thunderbolt display is more than a display; it's a Thunderbolt hub/dock with a display attached to it.



From this picture, you can see all the ports that the display comes with:


3 USB ports
1 Firewire Port
1 Ethernet Port
1 Thunderbolt Port


As such, this is not a mDP or DP monitor.  You need a Thunderbolt signal to drive this monitor and HDMI simply can't do it.

What will drive this monitor?

Per Apple's Support Page on the Thunderbolt Display....