Zdenek wrote on Jul 31^st, 2014 at 12:19am:

Hello, Thankyou for that information iam also interested in purchasing the 777 i was wondering if you can use the default fsx flight planner to do your own flights and then transfer them to the 777 fmc and then load it when you start it up. And also please can you tell me how big is the CS 777 download? Thankyou so much. :)

No worries.

I can't tell you how big the download is, I simply don't recall from when I downloaded it.

In regards to flight planning. The short answer is yes, in my experience you should be able to create a flight plan with the  FSX default planner, and then in the FMC you can select the option to load FS flight plans, however, FSX does not give you SIDS and STARS for departures and arrivals, so I have found I need to search the internet for charts of the airports I'm using and then manually enter the SIDS and STARS respectively.