First of all, thanks to everyone following this.
Now, just an update, think this could be helpful to find the root cause:
The users profile is directed to drive D, and the OS lives in C, this is for corporate reasons.
Many applications fail to install or to open if the environment variables, such as TEMP and TMP are directed to its default location %USERPROFILE%\AppData\Local\Temp while it resides on a drive different than the OS one.
And if I rollback to the default path SEP 12.1 won't uninstall or install.
So that's why we changed it to c:\temp
any thoughts?
Regards,
Roy_M