I have been having a problem with the PortableApps Start.exe located in the root of my drive. When I double click to start the launcher, it gives me "The PortableAppsPlatform.exe file is not a valid PortableApps..com release and cannot be launched." However, if I run the program as an Administrator, it will launch with no problems. I have done a virus scan of Start.exe on Virustotal and it shows a 0/46 detection ratio.
I am running Windows 7 Home Premium x64.