Custom ROM installation
Two ROMs are to my opinion worthy of testing:
The first one is close to the official ROM, and can be downloaded here:
http://android.modaco.com/content/htc-hero-hero-modaco-com/310731/30-jun-r5-modaco-custom-rom-for-gsm-hero-now-with-online-kitchen-android-2-1/
Select the rom "r5 with additions with radio image" in order to also update the radio.
Else, the VanillaEclair ROM is a basic ROM well optimized but without HTCSense. It can be downloaded at:
http://www.vanilladroid.com/forum/viewtopic.php?id=16
Choose "VanillaEclair 4.0 NAS @ 691/176".
Just copy the downloaded file to the SD card root folder.
Then, start the phone recovery mode (press HOME on startup) and launch the following commands to wipe the existing system and data:
Wipe -- Wipe data/factory reset
Wipe -- Wipe Dalvik-cache
Wipe -- Wipe SD:ext partition
Wipe -- Wipe battery stats (only if the battery level is at 100%)
Then apply the new ROM with:
Flash zip from sdcard
and select the ROM file. Wait for the end, and then restart:
Reboot system now