Steps to Install new ROM on HTC Desire and get Android 2.3 or Android 3
When rooteas not lose or configuration or data, or the desire apps, but from S-OFF you lose everything. It is recommended to backup the important things we create.
If you are unsure of something, documentate well first, you conjelar the phone and only serve as a paperweight.
Read -> Before you do anythig: cyanogenmod.com: Before you do anything
Download as -> You have to download and install the Android SDK and takes quite, so you can go about doing mienstras rooteas, S-OFF, etc..