When you buy a laptop or a desktop first software that you 100% need a good antivirus
then you need a good browser
then need a download manager for download file from your browser
then you need a media player to play some audio and video
then you need a office tool
now a days everyone install a torrent client also
then you need a system cleaning and tuning software
then you need a compression tool
then you need a image viewer
many other software also need for some work but basic that you need 100%
thank you