Account “lost” after using --datadir in Geth

Question

I am extremely new to Ethereum, just started mining a bit 2 days ago. I use Windows 10 and a GeForce GTX 950 card. I have had geth running smoothly for about 2 days, then it started filling up my AppData in my C drive, leaving only 4 GB of space left.

Out of desperation, I did something very stupid by trying to copy the entire AppData folder to my other drive and then I used geth --datadir to try to direct the huge amounts of file storage go into my other drive. When I tried to run Geth, it didn't work, so I used --datadir again to swap it back to my C drive and deleted my entire copied AppData folder on my other drive.

When I did geth --rpc again, it said no etherbase set and no accounts found as default

and when I do the ethminer.exe -G on another window, errors pop saying I have no set etherbase.

I have been mining for 2 days and I know it's not too much, but yesterday when I checked I had a bit of ether by using eth.getBalance and I know all my keys and passwords and addresses and stuff are all here somewhere, but I just don't know where and how to use etherbase and re-set it up.

I tried to log in again using personal.unlockAccount(eth.accounts[0], "password") but it cannot find my account. I don't even know where and how geth stores a local account.

I have my local account address on a sticky note it looks like af104bda8 etc etc (I don't think that's a key) and I remember my passphrase, my keystore folder had a file in it but after I tried copying AppData to another drive the file inside disappeared.

I'm very lost what do I do?

Answer 1

Instead of moving the keystore directory I would "copy" it to the new location and additionally store a backup copy in a cold storage location.

Answer 2

First run geth normally without datadir, e.g., geth console

Then check your accounts using : personal.listAccounts
It should display you all your accounts. When you've started geth for the first time without --datadir your private keys(accounts) and your blockchain are stored under

%APPDATA%\Ethereum (\AppData\Roaming\Ethereum) 
keystore : for private keys
chaindata: blockchain copy

so to use another location move this folder (Ethereum) elsewhere and use its new location in --datadir