<h5>Our users reported that one of our Citrix shared desktop servers uses a classic theme.</h5>
<p>Upon investigation, I have noticed that themes on the server are grayed out and cannot be changed. The server was using a classic Windows theme as you can see from the pictures below.</p>
<p><a href="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out.png"><img class="alignnone wp-image-2428 size-full" title="windows theme" src="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out.png" alt="windows theme" width="1102" height="652" /></a></p>
<p><a href="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out_3.png"><img class="alignnone size-full wp-image-2429" src="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out_3.png" alt="" width="531" height="149" /></a></p>
<p>I have checked the related Themes service and it was disabled. I&#8217;m not sure how this happened, but here&#8217;s how to fix this if you run into this problem.</p>
<p>Run <strong>services.msc</strong> from <strong>Run</strong> prompt<br />
Navigate to the <strong>Themes</strong> service.<br />
Double click on the <strong>Themes</strong> service and set the startup type to <strong>Automatic</strong> and Start the service.</p>
<p>Even after this change, I still wasn&#8217;t able to change the theme. I have also tried double clicking on the theme file which resulted in an error:</p>
<p>This theme can&#8217;t be applied to the desktop. Try clicking a different theme.</p>
<p><a href="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out_6.png"><img class="alignnone size-full wp-image-2432" src="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out_6.png" alt="" width="361" height="155" /></a></p>
<p>I had to do a restart and then the theme was successfully applied as you can see from the image below.</p>
<p><a href="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out_4.png"><img class="alignnone size-full wp-image-2433" src="https://www.wincert.net/wp-content/uploads/2018/01/themes_grayed_out_4.png" alt="" width="245" height="75" /></a></p>
<p>I hope this helped in case you had the same problem, if not, please leave your comment below.</p>

Cannot change Windows theme, grayed out
