I have a customer that has a new wave 15 Office365 tenant and click to run is not compatible with Windows XP. Like most corporate customers , my customer had a proxy.
So I ran the Office365 readiness assessment tool which you can download HERE
The results of the test stated that Office365 ports could not be contacted.
The reason for this is because Office365 communicates to the service via networkservice.
Lets say my proxy was 22.214.171.124:8080 then run the following command and Office will activate fine.
bitsadmin /util /setieproxy networkservice MANUAL_PROXY 126.96.36.199:8080 “”
If you need bitsadmin for xp you can download it HERE .