There's a great site, http://supportdetails.com which gives you a bunch of info on your system, browser etc - very useful when diagnosing IT issues.
They allow us to prefill the email sending fields, so create a macro with this in it as a " Comment/description " action:
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Please go to this link and click on "Send Details" to give us more information about your system:
h t t p://supportdetails.com/?sender_name={{ticket.requester.name}}&sender={{ticket.requester.email}}&recipient= support@zendeskdomain.com
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Just remove the spaces from the "h t t p" (I did that so this forum doesn't abbreviate the link) and change the last email to your helpdesk's email and you're done!
Zendesk Note: Our support team loved this tip from Jack so much they wanted to use it immediately. They tweaked the code slightly (see below) so that it updates the existing ticket, instead of creating a new ticket, and to account for spaces in names. Use the version that works best for you! (Don't forget to replace yourdomain with your Zendesk sub-domain.)
http://supportdetails.com/?sender_name={{ticket.requester.name| replace: " ", "%20" }}&sender={{ticket.requester.email | replace: "@", "%40" }}&recipient=support%2bid{{ticket.id}}%40 yourdomain .zendesk.com
Also, check out Eli Webster's script from July 9, 2015. It sends support details as a private comment instead of a public comment:
http://supportdetails.com/?sender_name={{ticket.requester.name| replace: " ", "%20" }}%20%7B%7Bpublic%3Afalse%7D%7D&sender={{current_user.email | replace: "@", "%40" }}&recipient=support%2bid{{ticket.encoded_id}}%40YOURDOMAIN.zendesk.com