before splunk6.0 version, may change logo by replace C:\Program Files\Splunk\share\splunk\search_mrsparkle\exposed\img\skins\default logo-mrsparkle.png, but the new version splunk6.0 , it seem not work.
how can change login logo in splunk6.0 ? thanks
The logo in version 6.0 is actually not an image, it is just styled text in the Splunk Font governed by the login.css file.
If you look at the login page with a tool like firebug or the developer tools in chrome, you'll see that there is something that looks like this:
<div class="prompt"> .....
Splunk is styled with the Splunk Font that is packaged with the product.