Simple installation Windows Mobile 6.5 DiamondTouch
1: First download this ROM from here BsB 6.5.1G: Direct Download
or view full post and look this ROM HERE
2: Download this RAR from here UpdateTools6.5-DiamondTouch.rar
3: Extract this rar, put your downloaded rom into RUU_UpdateTool folder
4: Make connection, Active Sync option using Windows Mobile Device Center or
5: Go to folder RUU-HSPL, start Custom_RUU.exe and follow instructions
6: After restart connect again using Windows Mobile Device Center or
7: Go to folder RUU_UpdateTool, start Custom_RUU.exe and follow instructions,
don't forget to copy your downloaded rom into this folder.
Note!: You must have 50%+ batery power to start flashing process.
With this instructions you can do perfect and safe installation of all roms.
If you whant other rom to flash, delete old rom from RUU_UpdateTool folder and paste new rom there and start process again.
If you got some error or broken installation with new rom and you can't start your OS again, just power on your device, press and hold volume button Down + Reset button simultaneously, when red/blue/white screen appears, connect your usb and start process 7: again or with new rom there.
Look This site and Try manu more ROMs available for your HTC http://all-cooked.blogspot.com/
I suggest This ROM, this rom is good and stable:
Full post HERE
If you using iGO8-Amigo navigation, install TouchFLO Deatacher for more free ram.