We have occasionally seen problems when users move from a trial to a full suite with Office and the general recommendation is to fully uninstall the trial first, reboot the computer, then install the full suite.

I know that is different to what you want to try, but these trials can be tricky. What would happen when the trial ends and the trial software becomes disabled and severely limited? I don't know.

I have heard that users can install different Office versions on the same system as long as they ensure that the two suites are installed in separate folders. I don't know how successful that is.

If you want to try this Office 2010 trial, then be prepared;

1] Create your own System Restore point before installing the trial software.

2] Have your Office 2007 CD handy, just in case things go wrong and you need to reinstall Office 2007.

Good luck.