My computer crashed and I was using the Bitcoin Core/QT client (they're the same right)? I thought I had my public and private keys saved, but those keys are from my old Armory wallet. I don't think I swept them to Bitcoin core, but I still used those keys for encryption/decryption. I was able to retrieve the wallet.dat file from the oldwindows data that is backed up on my computer, but I was wondering if I could retrieve my private key from the dat. file and how. Or if that isn't necessary, how should I go about reinstalling the bitcoin client so that I will have my coin back? I appreciate your help.
As long as you have wallet.dat file and encryption key so you have nothing to worry about.
You can reinstall Bitcoin-core and move your wallet.dat file to bitcoin directory (./bitcoin on Linux) then you will be able to use it like nothing happened.
To get your private keys from wallet.dat you could run in your terminal
bitcoin-cli walletpassphrase "PasswordHere" 600 bitcoin-cli dumpwallet "txtfile_keysFile_path.txt"
All your private keys will be stored in that path.
Just switch your old wallet.dat with the newly created one.
When my computer and Bitcoin-QT crashed, I retrieved and backed up the old data. Geeksquad can do this part for you if need be but it isn't difficult. Once I had the data and a fresh install, I went to retrieve the wallet.dat from my old computer files at C:user/username/appdata/roaming/bitcoin. I backed that up and made copies of the wallet.dat file. Next, I installed a new Bitcoin-QT client and started syncing the blockchain from scratch. Shortly after beginning the process of syncing, I swapped the newly created Bitcoin wallet.dat with the one that had coin on it. It's probably best to rename the new wallet.dat "backup wallet data" instead of deleting it, but it doesn't matter. It just matters that the wallet.dat that you want to use is the only "wallet.dat" file in the folder or it won't know which one to read. Once the chain was done, my coin showed up.