How to Run Android 2.2 Froyo on an HTC HD2

Early community builds ran Android 2.2 Froyo on the HTC HD2 from a microSD card through HaRET, leaving Windows Mobile in internal storage. This is an SD-card boot, not an official HTC update or a permanent ROM installation.

The FroyoStone Sense build in the old guide is marked discontinued in its original XDA developer thread. Its old download archive cannot be verified here, so this guide offers no replacement link. Continue only with a traceable build explicitly made for your HD2; do not run executables from an arbitrary mirror.

Before you begin

Confirm that the handset is an HTC HD2 (also called Leo) and still boots Windows Mobile. Match the build notes to your exact device variant. You will need a microSD card and either a computer card reader or the phone’s USB cable. The HTC HD2 user manual describes accessing an installed card through USB Disk Drive mode.

Back up the card and important phone data, charge the handset, and preserve the card’s original files. Android 2.2 is long obsolete: treat it as a preservation project, not a secure everyday phone, and keep personal accounts and sensitive data off it. These steps cover only the card-based method, not NAND flashing, HardSPL, or MAGLDR.

Run the Froyo build from microSD

1. Verify the build. Read its original release notes. Confirm that it targets HTC HD2/Leo and identifies Android 2.2/Froyo. Compare a published checksum if one is provided. If you cannot verify its source or compatibility, stop.
2. Extract the archive on a computer. Preserve its folder layout and read any included instructions. Classic HD2 SD-boot recipes use an Android folder plus CLRCAD.exe and HaRET.exe; paths can vary. Never mix files from separate ROM packages.
3. Copy the Android folder to the card’s root. When the package specifies this layout, put the folder at the card’s top level, not inside another folder. Use a card reader or USB Disk Drive mode. Wait for the copy to finish, then safely eject the card.

4. Open the folder on the phone. Insert the card, start Windows Mobile, and use File Explorer to open its Android folder. Confirm the required files and names match the build notes before launching anything.

5. Run CLRCAD.exe once. The classic community sequence starts this utility first. It may show no window; wait briefly rather than tapping repeatedly. If the file is missing or the package says to use another order, stop and recheck the notes.

6. Run HaRET.exe and wait. The display may go dark, show a boot logo, or show progress activity. Keep the card inserted and let the first start finish. Startup times varied, so use the release’s instructions instead of assuming a fixed wait.

What to expect and how to recover

If Android reaches its home screen, it has booted from the card; Windows Mobile remains the resident system. A normal reset returns to Windows Mobile, and launching HaRET starts Android again. Feature support for radio, camera, Wi-Fi, sound, and apps differed by build, and current services may not work with software this old.

• Windows Mobile starts after a reset: expected behavior; open File Explorer and launch the Android build manually.
• Files are missing: check extraction and folder placement. Do not rename executables or combine packages to guess a fix.
• Black screen or freeze: wait for the build-specific first-start period. If it does not progress, use the phone’s soft-reset steps in the manual. Do not flash an unrelated bootloader or download a random fix.

The Android Open Source Project’s compatibility page identifies Android 2.2 as Froyo, API level 8. The developer thread documents the historical build; neither source validates the safety or availability of old third-party archives.