title: how to set variable name for google cloud instance
body: <p>PROB_INSTANCE_NAME=INSTANCE_NAME</p>
  <p>not working</p>
  <blockquote>
  <p>C:\Users\HP\AppData\Local\Google\Cloud
  SDK&gt;PROB_INSTANCE_NAME=lamp-1-vm 'PROB_INSTANCE_NAME' is not
  recognized as an internal or external command, operable program or
  batch file.</p>
  <p>C:\Users\HP\AppData\Local\Google\Cloud SDK&gt;set PROB_INSTANCE_NAME=lamp-1-vm</p>
  <p>C:\Users\HP\AppData\Local\Google\Cloud SDK&gt;gcloud compute instances
  stop &quot;$PROB_INSTANCE_NAME&quot; ERROR: (gcloud.compute.instances.stop)
  HTTPError 400: Invalid value '$PROB_INSTANCE_NAME'. Values must match
  the following regular expression: 'a-z?'</p>
  </blockquote>
  <p>i am using google gcloud tool on the desktop.</p>
  <p>trying to install Linux guest environment by cloning root disk.</p>