I am writing this message again in order to maybe help other with the same problem.

My problem was
"I have problems starting Myst V:EoA.
I am using the original disc.
Installation is completed successfully it seems.
Detection tool report is OK.

If I start Myst I get the splash menu with the options of play, register manual etc. If I press Play, eoa.exe quickly appears in the TaskManager but then silently disappears. No log file is created.

If I start Myst with the Compability option set to Win 2000 I get the "Unable to authenticate original disc" message."

In order to solve it I updated both audio and video drivers as well as DVD-firmware. It was time to do it anyway but it didn't help.
No luck with uninstalling Nero either.

I got pretty desperate in my search of a solution and in the end I almost gave up. To think about something else I installed and tried to start Ghost Recon AW. This time I got an error message, message about "Securom"-process is blocked by another process. Otherwise same behaviour for both games.

With this new info I disabled Services and Autostart via msconfig and tried again. It worked!!! Autostart objects where no problem and I slowly started to enable service after service waiting for the dreadful behavior once again. Turned out that the very last service I enabled was the one responsible for the SECUROM message with GRAW and the silent behavior of MYST.

The process is SDHELP.EXE which is a help process of some use (don't know which) to Spyware Doctor.

Thanks Heimdall, for the help on trying to solve the mystery.