Portfolio backup

So i am planning to reinstall my windows and delete everything on the pc.
What is best way to create a backup file with all the information in it (securities, deposit accounts, securities, accounts, all the transactions, etc.)?
I tried to create an export xml file but i can’t load it…

Instead of exporting, use File > Save As ... XML.

If you would like to transfer your custom settings as well, see Loss of custom settings after moving a folder