Normally, you should just make a backup of your wallet.dat, install a new version and run it so it can start syncing, starting from the last time you synced your wallet... The actual data is stored not in the directory containing the bitcoin binary, but in %APPDATA%\Bitcoin (
https://en.bitcoin.it/wiki/Data_directory), so it shouldn't matter which path you start bitcoin-qt or bitcoind from.
This being said, 0.14.2 was released almost 2 years ago, i don't think there were reverse compatibility problems since then, but i'm not 100% sure.
The main advice is always the same: make sure you backup your wallet.dat before doing anything else... If you have your wallet.dat, you can basically scratch everything else and re-start on a clean machine