After running geth for a while, I found that I could no longer attach to a running session. The message I encountered was
Fatal: Unable to attach to remote geth: Timed out waiting for pipe '\\.\pipe\geth.ipc' to come available
. I was able to resolve this by attaching to the RPC (?) endpoint.
geth attach http://127.0.0.1:8545
Logging into the console (attach to a running session), to get current amount of Ethereum:
web3.fromWei(eth.getBalance(eth.coinbase), "ether")