not accepting connections.

[AWynn4964@aol.com]

I just installed  the free personal latest version of VNC on my  sister's pc, 
and mine so that I can maintain her pc from here, as she is pc  illiterate.
 
Problem is, I can connect to my pc from hers, but not from mine to  hers, 
which does me no good. I've used vnc in the past and never had any  trouble. 
 
Ive tried changing the port from 5900 to 5920 etc.
I've used a simple password ( a )
I've allowed my ip address to be trusted by her antivirus program  (Mcaffee)
 
but still when i hold her cursor over the VNC system tray icon, it says  "not 
accepting connections."
 
any ideas?