Has your phone been hacked in any way?
Assuming not, read this one:
HERE
I still cannot fathom why you cannot follow this though. Something looks like it is not standard. I am now wondering if you have had an after-market hack to enable use with other networks and this has intentionally blocked updates (preventing the lock from becoming re-introduced).
The following should be available to you:
##
Update your software
To update your Hero over the air:
Go to All Applications
Tap Settings > About Phone > System Updates > HTC Software Update
Select Check Now
Follow the on-screen instructions to download and install the update
Note: If the HTC Software Update is not visible on your phone, continue to the computer download instructions below.
_____
To update your Hero through computer download:
Important Note: Installing the 2.27.651.5 update will delete all the data and information on your phone. You will lose contacts that have not been synced to an email account, text messages that have not been forwarded, saved voicemail messages older than 5 days, voicemails older than 20 days that have not been listened to, and call history. The calendar and email settings will also revert back to factory defaults. Pictures, music, videos and files are stored on your microSD memory card, which should be removed before updating your phone.
Before you start the download, make sure:
You back up your data
To save important text messages, forward them to an email address:
Tap the Applications tab and then tap Messaging
Select the text message you want to save and hard press it; you will see a menu to Forward the message
Any installed applications downloaded from the Android market must be re-installed. To re-download applications:
Tap the Applications tab and then tap Market
If prompted, sign in with your Google account credentials
Tap My Downloads
You will see paid applications in the list shown
Take note of the free applications on your phone, as they will have to be searched for again and downloaded manually after the update
Your Hero has a fully-charged battery
You have the USB data cable that came with your Hero
You have closed all running applications on your computer and disabled standby and hibernation modes
You have installed HTC Sync on your computer
Go to HTC's support site
Click on the Download link for HTC Sync
Select Run in the dialog box and follow the on-screen instructions to complete the installation
To download the update software, go to our HTC Hero download site
Download the RUU ROM Update Utility and save it to your computer desktop
Double click the .exe file and click Run in Windows XP or Yes in Windows 7
On the Welcome Screen, be sure to read the caution message and Read Me file; check the box next to I understand and click Next
On the next screen, follow the steps listed and click Next
You will see the message Verifying information on your Android phone. Please wait