If you still own HTC HD2, Android should be the operating system on it instead of old Windows Mobile 6.5. And the good news, there are still lot of developers working hard to develop Android ROM for HTC HD2. TyphooN CyanogenMod 7 is one of them. And it is based on latest Android 2.3.7 Gingerbread GWK74 and using latest Tytung r12.4 Kernel. Besides, it is equipped with latest SuperUser 3.0 and new Android Market 3.1.5 too. And I like the new ring lockscreen style in CM7.
Android 2.3.7 CM7 on HTC HD2
Note – Just reboot if you faced hang issue on first boot (after 15 minutes).
Installation guide ~ How to Install CWM NAND Android on HTC HD2? (Video)
Download TyphooN CyanogenMod 7 v3.6.8 [Kernel: Tytung r12.4] NAND A2SD+ Zip ROM here.