CANT PHONE ANYONE

Free unlocking codes is not safe for your HTC HD2 .Because they will hard lock your HTC HD2 or lose your data. call your service provider to get your HTC HD2 Imei Unlock Code. or buy this HTC HD2 Mep Unlock Code by third party. third party would charge little amount. and give your unlock code instantly. and it is safe and trusted. i hope third party would be solve your problem:)

Did you unlock it via the same place you bought it from? Did the phone ever work? (connect calls/send text ?)
If it had worked before try a hard reset.
Restart the phone, as soon as the phone switches off (screen off) hold the power button, volume Up and volume Down button all at the same time.
You will see a grey screen with blue text warning about a hard reset, release those three buttons and press the Vol Up button to confirm the reset.
Do these steps with the simcard you want to use already placed in the phone, so you can go through the setup of a new phone connection when the phone boots up after the hard reset.
NOTE: The Hard reset will get your phone to factory settings, so you will loose all data in your phone memory (sms, emails, phone logs, calendar, tasks, etc) All the data in your memory card would be safe though.
Let me know how it goes.

It was possibly not unlocked properly. When you bought it, what carrier was it locked to? You can buy an unlock code on ebay for about $10:

http://shop.ebay.com/i.html?_nkw=HTC+HD2+unlock+code&_sacat=0&_dmpt=PDA_Accessories&_odkw=Motorola+Motozine+screen&_osacat=0&bkBtn=&_trksid=p3286.m270.l1313

Cant make calls on my htc hd2 operation failed

As far as i know free unlock codes does not work properly i am saying this because i lost my phone by this.then my friend suggested me the site from where i got my unlock code.its not free but it as cheap as free.click here to get your unlock code.

hope this helps..