Sony Xperia ZR fastboot driver I am trying to get the fastboot driver for Sony Xperia ZR (dogo) for Windows 7 x64.

I found a page with instructions which pointed me to a Sony site where you can download a android_winusb.inf file which one is supposed to copy over the one in the Android SDK folder under extras\google\usb_driver\.

Then, I put the phone into fastboot mode by


Powering it off 
Pushing the Volume Up button while connecting the phone via USB to the PC. 
The light turns blue and in the Windows Device Manager, I can see a new S1Boot Fastboot entry under Other devices.


After right-clicking on that entry and selecting Update Driver Software..., then Browse my computer for driver software, I pointed to the Android SDK folder where I previously put the android_winusb.inf file (see above).

Unfortunately after clicking Next, there is a message Windows was unable to install your S1Boot Fastboot and Windows could not find driver software for your device.

On this thread, I found a link to a thread on XDA Developers where one can download a "fastboot package" and "32/64bit drivers", but I am hesitant because these are EXE files from an unknown source and the thread's title suggests this is for Xperia Arc, not ZR.

Are there any "official" drivers for my phone?

UPDATE:

I also found a great Sony webpage listing "All Android downloads" which has white papers, source code and drivers for all(?) devices, except the drivers for the ZR are missing.

UPDATE 2:

I have seen this comment to a question concerning fastboot drivers and USB device IDs, so I tried to replace device IDs for SingleAdbInterface, CompositeAdbInterface and SingleBootLoaderInterface (sequentially, not all at once) with the one which I got from the Device Manager, which is USB\VID_0FCE&amp;PID_0DDE&amp;REV_0100. Unfortunately this didn't make any difference, the drivers are still not recognised.
While playing around with the INF files, I found that the one supplied by Sony actually does work, you only need to "force" Windows to use it for your device. I am not sure if that has anything to do with the unsigned nature of the driver or that Windows cannot verify that the driver is compatible (see below), but it simply doesn't seem to accept the driver with Sony's INF automatically.

I order to install the driver, I did the following:


In the Device Manager, right-click on the S1Boot Fastboot entry and select Update Driver Software, then Browse my computer for driver software and Let me pick from a list of device drivers on my computer.
Select Show All Devices, then Next.
Click Have Disk... and then Browse... to the android-sdk\extras\google\usb_driver directory.
Then the Model list is populated with three entries, select the one called Android Bootloader Interface and click Next.
Click Yes on the Update Driver Warning message mentioning that Windows cannot verify compatibility of the driver with the device. 
Click Install this driver software anyway on the Windows Security message saying that Windows can't verify the publisher of this driver software.


After that, I was able to run fastboot commands on my device (I only tried devices and reboot so far). 

On a side note, I found it interesting that you actually don't need any specific driver binaries such as DLLs from Sony and that the drivers supplied with the Android SDK seem to be sufficient, except for the INF entries with the correct device IDs.