Did you install the Sync utility first?
Installation instructions
Download and install the HTC Sync software available here:
HTC Mobile Phone Support - HTC Hero™ (Sprint) - Downloads
Download the update file for the HTC Hero available here:
HTC Mobile Phone Support - HTC Hero™ (Sprint) - Downloads
Connect your HTC Hero to your PC using the supplied USB cable
If the HTC Sync application appears on the screen of your PC, you may simply dismiss the wizard by pressing the Cancel button
Run the RUU update file for the HTC Hero
Follow the on-screen prompts to install the update for your HTC Hero
WARNING: During the upgrade process, do not attempt to make/receive calls, press any buttons on your device or disconnect the device from the USB cable as this will stop the update and your device may be rendered inoperable!
Download via FTP (118 MB) Download via HTTP (118 MB)
HTC SYNC UPDATE FOR HERO (SPRINT) (2.0.33) | 04.23.2010
HTC Sync™ lets you synchronize Outlook and Windows Address Book (Outlook Express), contacts and calendar events on your PC with your phone. It also lets you install third-party Android applications on the phone, and the Mobile Network sharing function as well. more
Download (38.54 MB)
HTC Mobile Phone Support - HTC Hero™ (Sprint) - Downloads