I recently purchased the pro-pack upgrade from the Microsoft website to take my windows 8.1 base version to pro so I could use the remote desktop connection.  I can use this under my account which has sysadmin priviliges.  I don't want to have to have these priviliges to use RDC - so I went to the System Properties -> Remote tab to add specific users - and I cannot - the box to do so is greyed out. (I apparently can't post the image until my account is verified)

It should not be greyed out in the pro-version.  After some research it turns out this is an old problem as detailed elsewhere on this forum. The issue was fixed for the windows 8 pro-pack upgrade in July 2013.  I have currently spent 7 hours-ish online and phone with Microsoft trying to explain the issue and point out the fixes suggested, which is like banging my head against a brickwall, and now they want to charge me a support contract for fixing the issue.  Hence can anyone shed further light on this issue before I have to submit to this extortion. Specifically does anyone know whether the fix (KB2855336) was applied to windows 8.1 ? I have explicitly tried to apply this fix to my system but the standalone installer told me that it was not applicable to my system, presumably on the basis my system is 8.1

Hello craigdrobinson,

About the screenshot, please upload it to the OneDrive and share it with us.
Upload to OneDrive: http://windows.microsoft.com/en-us/onedrive/add-photos-files
Share files: http://windows.microsoft.com/en-us/onedrive/share-file-folder

Based on my test, I cant install the update KB2855336. And in the system requirement list, the Windows 8.1 is not listed. It is applied to Windows 8 , Windows 2012 and Windows RT.

For more information, please take a look at the following KB.
https://support.microsoft.com/en-us/kb/2855336

Best regards,
Fangzhou CHEN

You could also just add the users you want to the Remote Desktop Users group. Right click the Start Button, click Computer Management, expand System ToolsLocal Users and GroupsGroups, right click Remote Desktop Users, click the Add button, type in the user name you want to give access, click OKOK, close Computer Management. (Alternatively you could go to Local Users and GroupsUsers, right click the user you want to give rights to, click Properties, select Member Of, click Add, type in Remote Desktop Users, click OKOK, close Computer Management.)

Brandon
Windows Outreach Team- IT Pro
Windows for IT Pros on TechNet