Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Ok I resovled this issue but its a weird one and could be an issue with the upgrade from 2010.
I used procmon.exe to find out which reg keys outlook.exe was htting when I clicked the Sign In button (which triggered my issue) and found this was the key in question:
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Common\Internet:UseOnlineContent
UseOnlineContent was set to 0 (zero) and so I changed it to 1 (one) and after restarting my Office 2013 products I was able to sign in to Skydrive using them.
I hope this will be of help to anyone experiencing a similar problem.
Cheers,
Tim