lost software...help!!!

I was working yesterday and was prompted to update parallels. When I did so it updated and then asked if I wanted to reboot which I declined at the time. When I finally rebooted I received an error which I remedied by reinstalling parallels tools. Unfortunatley, for some reason my Sigmaplot program was uninstalled from Windows. Is it gone forever? I could not find it in my recycle bin and it is not in the install/uninstall program files section of control panel. I could not even find any executable file on my Mac whatsoever.