HTC Desire :: Rooted / Red Triangle Not Changed Still Cannot Flash ROMS

This is where I am now near enough after a day of doing this. I rooted my phone initially and it seemed to work, I had superuser permissions but it didn't seem to be fully rooted, I couldn't flash any ROMS and when in HBOOT setting, when I tried to go through the recovery part to flash the ROM the red triangle just stayed there it didn't change. I thought if I rerooted it may help, so I did, with the same step by step guide, however when I connected the phone and opened the windows push batch files the red triangle didn't change and I had to disconnect and turn the phone back on.

So now I have my phone which I do not think is fully rooted as the push files didn't work properly and I cannot flash any ROMS as I cannot run the recovery mode properly or get to use clock work mod as the red triangle is just always there. Everyone seems to have been having success and I just cannot seem to get anywhere. I have tried so many things from downloading custom ROMS from modaco etc. but I cannot flash any ROMS and now I'm just stuck. If there is a way I can properly just root the phone and flash the ROMS id be happy, I feel like I know what to do, but I just do not understand why when rooting, the last part when u connect the phone and open the push files didn't work, and also why when i thought the rooting had worked the first time, i still couldn't get to the part where I flash the ROMS.