Lumia 710 devices and some models of the 800 can now make use of Interop Unlock, thanks to members of XDA. With this, owners can get access to the phone's drivers and deploy unofficial applications.
All Nokia Lumia 710 handsets can take advantage of Interop Unlock simply by downgrading the bootloader. This can be done by downloading and flashing special firmware with Nokia Care Suite and then loading the Interop unlocked ROM.
As for the Lumia 800, it seems a test has to first be undertaken in order to ensure the device is compatible with the procedure. Those who have a device with a locked bootloader cannot flash the required ROM.
Interop Unlock offers owners the ability to install home-brewed applications on devices running Windows Phone 7.5 Mango or above. Starting with this version, Microsoft blocked this facility so the usual unlock methods would not work for those who wish to install registry editors, file explorers or any other software that uses interop drivers.
Until now this procedure was out of bounds for Nokia owners, with the hacking community already making progress on Samsung, LG and HTC devices.
The patch is currently in an alpha stage, with several applications still failing to work. Also, the installation can only be completed using the fastboot protocol. The full guide is available in the source below.
Source: XDA (opens in new tab)