Bit of an abandoned forum these days mate, Desire being a bit 'old hat' and all. XDA Dev is where it's still alive and kicking.
There is a lot of info but to be fair you should still be able to find what you need, if you don't have patience, don't bother getting into this, leave your phone as it is.
However, I can help point you to the right tools:
First : go here: http://unrevoked.com/recovery/
and d/l the required exe
Before you run it, make sure you have a) downloaded and installed HTC Sync THEN Uninstall it but leave on the USB driver
Run the unrevoked exe with the phone plugged in and with USB debugging selected (via settings - Development blah blah you'll find it)
If it doesn't detect your phone, install these drivers (providing you are Windows based)http://unrevoked.com..._driver_install
That should work fine.
Don't bother trying the S-Off option it doesn't work for GSM phons (unless someone can advise this has changed)
Your phone is now rooted.
Oh did I mention S-Off above? Lol. Mate start with the root then move on to the next step. You can start flashing ROMS once rooted, S-Off gives more capabilities but I'd advise you get some experience of the mod world first.
Hope that helps.
Also here's the XDA Dev link: http://forum.xda-dev...splay.php?f=594
and a link to a post of all steps above prob explained better: http://forum.xda-dev...ad.php?t=696189
Edited by BashyUK, 22 February 2012 - 01:39 PM.