Symantec Install Package :Offline Install Error

I was trying to create an offline package for SMP CMS 7.1 SP2 and I was able to create the package using the Symantect Installation Manager 7.5. When I click the exe file after the package is created, I am getting the following error: "Symantec_Install_Package_XXXXXXX is not a valid Win 32 application." 

I didnot get any errors while the package was created. I see the file on my desktop with a size of 6.28 GB.

I am using  Win 7 64 bit machine for this whole process. Is that the issue?