I'm running windows xp
Then UAC is not your problem. In XP, programs are allowed to create files in Program Files.
In the installed version, open Saira.ini and turn on portable mode:
Portable Mode=1
This will change where it places save files, hopefully fixing your problem.
Non-portable mode (installer) places saves somewhere in your user folders.
Portable mode (zip) places saves in the Saira folder itself.