Check your system drive (probably C
for a Windows.old folder. (If you don't see it in the Windows File Explorer, click on the VIEW tab at the top and check the HIDDEN FILES box.)
Once you located the above mentioned folder, go in there, then USERS -> <your username folder> -> DOCUMENTS.
Simply copy the files in there to your current DOCUMENTS folder and you should be good to go. Check also your old PICTURES and VIDEOS folders in case you had something in there too.