Posted by Jayce Ooi as How to
How to revive SD card after install Windows Phone 7 on HTC HD2? Yes, Windows Phone 7 ‘kills’ your SD card during its installation and partition with its own file format. Your SD card is practically useless now unless you revive it by repartition it again. No worry, I just revived my SD card and you can do the same too.
How to repartition SD card after install Windows Phone 7 on HTC HD2?
Note – only touch SD card partition. DON’T do anything to your hard drive.
Method 2 ~ Suggested by Amit
Load MAGLDR. Go to Services. Select clearsd MBR option. This will remove the hidden partition.