In your OP you said "set default driver of the game to nvidia." What did you mean by this?
Try updating your Intel Drivers:
https://downloadcenter.intel.com/default.aspx
http://www.intel.com/p/en_US/support/detect?iid=dc
If it refuses to update them because it says "use manufacture drivers" we can try to get around that by completely uninstalling, forcing the generic VGA driver and installing Intel's after.
Garden Ops is hosted by Players. Because of that is is flakey at best.
Only thing you can do is ensure your ports are forwarded and hope the host has his forwarded and has decent internet.
Hosting will be your best bet.
This can be used to check the ports are done correctly:
http://portforward.com/help/portcheck.htm
The webbased port checkers don't work like that one.
Maybe this?
http://www.whatsmyip.org/port-scanner/
The problem with online port checkers is they assume you are "listening" on that port to begin with. I haven't dug around but my guess is PvZ doesn't listen to all those ports all the time. I suppose 'netstat -a -n' would tell us the answer but I can't test right now.
They also can't test UDP because UDP doesn't have any handshaking going on. It'd be safe to assume though if you forward TCP/UDP and TCP is reported working, UDP should be too unless a firewall or something on the computer.
I'd try running that program as Administrator or possible Compatibility settings... dunno, honestly I've never used it.
