user88842: I am running a full node using Bitcoin Core GUI on Windows 10. The conf file is in my bitcoin data directory, instead of being in the appdata/roaming folder. But Bitcoin-qt points to it by default and seems to work fine. 
But bitcoind and bitcoin-cli are looking for the conf file in the appdata/roaming folder, which I guess is the reason the bitcoind server never appears to start. How do I start bitcoind and check if it is running or not? I need bitcoind to run so that I can use json-rpc commands. 
If I run bitcoind on cmd, it appears to start downloading the whole blockchain again, which is unnecessary because I already have all of it.

user85140: You can use the --datadir parameter to specify the exact location of your blockchain data, and --conf to specify the location of your configuration file.
From the wiki:

If you want to store the data in D:\BitcoinData then click on "Properties" of a shortcut to bitcoin-qt.exe and add -datadir=D:\BitcoinData at the end as an example:
"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe" -datadir=d:\BitcoinData
Start Bitcoin, now you will see all the files are created in the new data directory.

If you have a custom config, do the same with the added parameter:

"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe" -datadir=d:\BitcoinData -conf d:\Bitcoin\bitcoin.conf


88842: <p>I am running a full node using Bitcoin Core GUI on Windows 10. The conf file is in my bitcoin data directory, instead of being in the appdata/roaming folder. But Bitcoin-qt points to it by default and seems to work fine. </p>

<p>But bitcoind and bitcoin-cli are looking for the conf file in the appdata/roaming folder, which I guess is the reason the bitcoind server never appears to start. How do I start bitcoind and check if it is running or not? I need bitcoind to run so that I can use json-rpc commands. </p>

<p>If I run bitcoind on cmd, it appears to start downloading the whole blockchain again, which is unnecessary because I already have all of it.</p>
 85140: <p>You can use the <code>--datadir</code> parameter to specify the exact location of your blockchain data, and <code>--conf</code> to specify the location of your configuration file.</p>

<p><a href="https://en.bitcoin.it/wiki/Data_directory" rel="nofollow noreferrer">From the wiki:</a></p>

<blockquote>
  <p>If you want to store the data in D:\BitcoinData then click on "Properties" of a shortcut to bitcoin-qt.exe and add -datadir=D:\BitcoinData at the end as an example:</p>
  
  <p>"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe" -datadir=d:\BitcoinData</p>
  
  <p>Start Bitcoin, now you will see all the files are created in the new data directory.</p>
</blockquote>

<p>If you have a custom config, do the same with the added parameter:</p>

<blockquote>
  <p>"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe" -datadir=d:\BitcoinData -conf d:\Bitcoin\bitcoin.conf</p>
</blockquote>
