Hi, a number of possibilities.
BTW, does the card work when inserted in a recent laptop or newer card reader? Or it doesnt work anywhere?
1- The adapter does not support SDHC (Secure Digital High Capacity) and the card is SDHC (you havent specified what card it is, so a guess).
2- The card has a controller firmware issue, and the controller is detected but the card cannot be understood properly by windows.
3- The card is physically faulty, broken traces, solder of chip broken, resistor or capacitor or other discreets faulty
4- The data on the card is corrupted in such a way that when Windows tries to read it, it crashes the programming logic
5- The blocks that are available for bad blocks to be remapped to are all gone, various devices handle\dont handle this in various ways
6- The card is totally full of data, some cards cannot function if all available space is used(Rare)
7- An actual bug in the cards circuit/firmware/controller (fairly rare)
In order, I am going to lean towards 2,1,3,4
If you want data recovered, then PM me as I am pretty certain I can recover. I would not insert the card into any machine if you want data recovered, and give it to a flash recoverer
regards