If under Linux or XP,
- install VirtualBox (or some other virtualisation tool) (
emerge virtualbox
for Gentoo) - get a Windows 7 ISO (no, wine will not work) (no, XP won’t work either, at least the 64-bit version has troubles with the the adb interface drivers)
- install Windows 7 in VirtualBox
Then,
- connect the Desire (make sure USB debugging is enabled)
- install HTC Sync, that will install the Android driver for the Desire (no, the Google USB drivers from the SDK won’t work)
- install the adb drivers (download from here)
- download and run the unlock app (previous version)
If running from VirtualBox, make sure the USB port is forwarded to the guest OS.
If the phone won’t reboot, make sure adb devices
shows the connected device.
If not, make sure the drivers are installed.
If the phone reboots, but the app won’t find it, again, make sure adb devices
shows the device. If not, make sure the adb drivers are installed too.
This will only work on the Desire.