I don't understand you. Do you mean Blockchain.info or the Blockchain of your Bitcoin-Qt? You can recover your private key / funds on Blockchain.info with your identifier, password or seed.
It is on blockchain.info. I stored it with a folder containing multiple documents in drive D. And after installing win it was lost.How to recover my private key ? Plz help me
You have to map your drive "D" in your newly installed Windows. I am sure that you can find some good guides how to do that.
You can PM me.
I support him via PM.
OK good luck
. I would recommend at the end to do not keep such value of BTC on blockchain.info.