Hi there, and welcome
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Not sure about the authentication error, but if you install a program to your SD card instead of main memory, you have to create a shortcut and put it in your \Windows\Start Menu\Programs\ directory. I recommend 'Total Commander' to do this, as it offers a lot more functionality/customization than the standard, built-in file explorer.
and about the LogMeIn service, I think that mobile plugin they made you install was for Internet Explorer Mobile, so use that instead of Opera (the default).
Hope this helps