Some people might have issues with STO if they choose to install in a location other than the one recommended by the Cryptic Installer.
If you do have issues go into the install location of STO, open theCryptic Studios folder, then open the test file named "Error". If there are any errors about being able to write to a game file (see attachment), then you can correct his by telling Windows to run STO under Administrative priveledges.
To do this right click on the STO Application (Star Trek Online), open up the properties and then click on the Compatability tab. At the botton click the check box that says "Run this program as an administrator".
Then open the folder named Star Trek Online, then Live. Find the file named Game Client and do the same thing for that file as you did for the other one.
This will allow STO to write information to the program files. I was having issues in Beta and noticed that I was getting these write errors at the same time I was getting client crashes. Some research led me to this information about not installing in default folders and such.