Flight plan files w7 32 bit

For some reason I can not safe a flight plan. It seen that I have no place to safe any flight plan in fsx . I will appreciate if some one can guid me to the location of the fsx flight plan file. I look in documents fsx and I can not find it. I located the pmdg flight plan folder, but not the regular fsx flight plan folder.

And also can some one tell me how to let the Cfg file in fsx to rebuilt fsx , and if these procedure will affect the pmdg acft .

I appreciate any help.