PC Mover can not deal with all license transfers since that would be a casual piracy issue. This means apps like MS Office might more but require a license key or a reinstall.
This really upsets those that had that special license where you got an Office (2007 to about 2016) with a PC but the license was locked to that PC.
Anyhow Office 365 should be able to open the usual doc and excel files. You might have something else but I don't see that detail here. The steps to open the old file would be to run the Office 365 product you need such as Word or Excel and in Word or Excel use it's File, Open to open that file.
In parting I avoid all that by using LibreOffice from Ninite.com. I have zero license issues here and I can get this app for Windows, Apple and Linux. All free too.
I recently bought a Lenovo P51 with Office 365 and after using PC Mover to transfer all my files I am unable to open my Office Professional 2010 files. I get this message:
"Microsoft Office Professional Plus 2010 cannot verify the license for this application. A repair attempt failed or canceled by the user. The application will now shutdown"
I bought the computer years ago from my employer who is now defunct and have no idea what the license number is.
I have a license for my current version of Office 365.
Is there any way to work around this issue and open my 2010 files?