Life is meant to be simple after all
Anyone who is having the same issue with sd card after Windows Phone 7 or 7.5 installation just repartition and reformat your card via 4ext recovery and it will work...nothing else needed :} Good Luck!
All credits to 4ext recovery developer....and the developer must be proud to find this info.
Here is Step by Step process-
If you are running Android NAND and have 4ext recovery installed....then
1. Turn off your device
2. Take out the SD card(if there is any in it) and insert the one you want to unlock/fix
3. Turn on your device HOLD red power button until you get to aMAGLDR v1.13 menu
4. Go to option 8. AD Recovery hit green button for it load
5. Now you should have 4ext recovery(mine is version 2.2.7) menu
6. Scroll down to Advanced
7. Choose> Partition SD Card
8. Choose whatever size you want to first one, second one to be and the rest goes to fat. If you want all in one partition, just choose '0' for the first two and '0' as swap.
9. Follow on screen instruction you may see.....and it will delete all previous partition and create new one
8. NOW go back to main 4ext recovery menu....and format you SD card...AND there it it! Your SD card it back to normal...enjoy
NOTE: I use 4ext recovery that you flash via usb flasher thru magldr NOT the one from market. You can find the flashable one in here. I will try to find the link and post it. BUT it is not and will not be my work!
Here is a link I found....but this NOT what I used. I used this recovery that I found in one ROM link I have tried in the past which I can't think of but I have been using the same recovery since then because it is the BEST with the option of EXT4 file system....the one I have you can directly flash it like any other recovery you normally would to partition NAND to flash NAND Android roms. Nand partition size has nothing to do with sd recovery steps.
Since I did not use the above option....I won't be much of help. But from my understanding you can use this option to update your current recovery to 4ext recovery and then follow my steps. The app from the market would require to update your current recovery as well to be able to use my method to restore your SD card after WP7 installation Good Luck! Although it is a very simple process to undertake, I am not responsible if you damage your phone or the sd card even more!!!
If someone who has the usb flashable version of 4ext recovery(for HD2) could attach it or provide link that would be great for everyone. Mine is installed in the phone and I don't seem to have that file....too many files I download everyday and must delete them all at some point