I have a 32GB Sandisk microSD. As an experiment I tried it on a Windows Phone 7, and as expected it said it was not fast enough.

microSD was for a month on a shelf.
Now, I can't see it in any PC I have, neither with nor without microSD->SD adapter. Disk manager does not see it at all. Diskpart does not see it.

I am not sure if that killed the microSD, or if its fs was modified to some extent to make it unreadable. But, I should at least see it in diskpart / diskmanager.

I am afraid its dead. What do you guys think?

If you put it into a Windows Phone 7, something special has to be done to return it to general use. The card is locked down to the phone only at this point, using the secure part of "secure digital" card. Look up instructions for unlocking SD cards, some devices like a Symbian phone make it very easy.

All the tutorials and articles and posts I can find, assume you can actually see the microSD card in your PC (or phone, but the phone option is currently not viable for me). You may not access the FS, not have a letter assigned (in Win), and you may have to resort to disk management tools to format, which is ok and also what I would expect, but still they assume your PC sees the card. In my case, PC does not, at all. There's no device of any kind I can operate on.

Looks like a Nokia is about the best chance you have or maybe a Sony Ericsson phone:

http://lifeinthefastlaneok.wordpress.com/2010/11/20/microsd-card-use-with-windows-phone-7-device/

http://forum.xda-developers.com/showthread.php?t=840351

http://forum.xda-developers.com/showthread.php?t=840524

Shonky and Drakino, thank you so much. Shonky, so my search skills were really poor. Your links were all that I had been looking for. I just plugged my 32GB microSD in my gf's Nokia, and formatted it. I took few seconds.