Uncle has installed 10 and has found hardware issues, drivers for printer and scanner not playing with 10, which MS are aware of and looking into..also problems with media player....I am waiting 'till Xmas to down load ! give them time to sort these problems out...
The printer one might be sorted by going to devices printers then right clicking on your printer and making it the default. If your printer doesnt show a reinstallation with the latest drivers from the manufacturers website should resolve that