If by the trial version you actually mean the release candidate, then no: you were warned at the time that you downloaded the RC1 that you would need to perform a clean install to replace it with the official release version. However, if you have a spare partition, or external drive, you can use Easy Transfer (saying "This is my old computer" to copy all your settings prior to re-installing. After reinstalling you will need to run the Easy Transfer again (saying "this is my new computer") and pick up the files from where you saved them.
Ensure that you have the latest version of Easy Transfer before starting:
http://windows.micros...windows-easy-transfer
So it goes like this:
Boot your existing system
Download and install Easy transfer from link above
Run easy transfer and save your settings to another partition or external drive
Clean install the Full Release of Windows 7
Install any other programs
Run Easy transfer to recover all your original documents and settings.