I've done all these things but still it tells me it can't connect with the server, although my cable Internet is working very well for everything  else. Any more suggestion would be very welcome. 

I have split you off from that extremely old topic.  The Microsoft FSX servers for Activation have been taken offline for a long time now.  You could try the phone number for your area that should be in your Main FSX folder. (good luck with that)!  Only other alternative is to purchase FSX Steam Edition.

Welcome to the AVSIM forums! 😀

The folder you are looking for is titled "Phone Activation.xml

There is a registry modification that works to activate FSX. As well as running as admin.

Just a fyi, I recently reinstalled FSX DVD version and the online activation did work.

I was actually shocked because the last several times I installed FSX a few years ago a phone call was required for activation.

Sometimes it works, sometimes it doesn't.  FSX Steam Edition has no such issues.

Also, when installing either FSX or FSX Steam Edition, do not install to the default directory when using Windows Vista, 7, 8, or 10.  The security on the default Program Files directory often causes issues with games and sims.  Install to a directory that you create.

Edited January 24, 20215 yr by stans