There is nothing like participating in that hot new ICO and sending your coin to a random ETH address in hopes that you won't be scammed. Being in the US, I don't have the pleasure of worrying about this anymore. For those that still have the opportunity, it's not always clear where your tokens are and how to access them on the Ethereum blockchain.
Check out this video walkthrough on how to find your ERC-20 tokens and add them to your wallet! This video specifically covers the MetaMask wallet, but my method could easily be used for any wallet that supports ERC-20 tokens.
Want to read the article instead of watching the video? Here is my original article on this topic: https://www.cryptostache.com/2017/10/23/tokens-find-ethereum-based-tokens/
Are you still having trouble after watching this video? Let me know and I can try to help or do a specific video on how to find and add your ERC-20 tokens to a different wallet. Until then...