Here is a detailed guide on how to install Windows Phone 7 on your HD2.
Disclaimer: Please try this guide on your own risk. Mobility Digest or I are not responsible for any damage caused your device from using this guide.
Steps before you begin:
Make sure you have HARDSPL 2.08 installed on your phone. If you do not then you can get that here.
Make sure you have at least 50% battery.
Make sure you have a radio version that is something like this 2.xx.50.x. If you dont then you can get that here.
Once these steps are done we can begin.
Make sure you have a backup SD card and not the one you normally use. You could lose all your data on the card.
Flashing Windows 7 on HD2:
Download the Windows Phone files from here. Extract the files on to your computer somewhere and this is what you should see after you extract the files.
Next connect your phone to your computer and your phone screen should look something like this. you can just leave it on the home page and dont need to be in bootloader mode or anything.
Once that is done open the MAGLDR12 folder from the extracted files and then double click on ROMUpdateUtility.exe
Read the ROM update instructions and click through them.
Once you click through it the phone should enter bootloader mode automatically and you should see a progress bar on your phone and on the computer.
Once the ROM update is done your phone will automatically boot and you will go into this screen.
Scroll down to USB Flasher by using the volume up and down keys on the left side of the phone and then hit the green answer call button.
Once you do that you will see this screen next:
Once you see this screen. Go back to your extracted files on your computer and open the folder LEO70_ROM and there you will see an application called DWI run that application as an administrator if you are on windows 7.
Once you do that you will see a batch of these screens. Read the information and click through them.
After that screen shows up for a while here is what you will see on your phone:
Once this is done the phone will reboot and you will see this screen.
Which will be followed by this screen.
After that screen you will have entered windows phone initial setup process and from there everything is self explanatory.
In order for the phone to recognize your memroy card if it has not already done so go to: Settings>about>reset. AGAIN MAKE SURE YOU HAVE A BACKUP MEMORY CARD IN THERE.
THANKS TO XDA AND DFT TEAM. I will be updating this post soon with instructions on how to get back to WM 6.5 if you choose too but for right now I wanted to get these instructions out.