According to preliminary estimates by Gartner, Lenovo was the world's largest PC vendor in 2018 in terms of units shipped. The Chinese company was at the top of the pile for the last quarter of the year (4Q18) and beat out HP and Dell for the year overall. However, Lenovo only came third for 4Q18 shipments in the US, behind HP and Dell.
https://www.notebookcheck.net/Lenovo-leads-PC-shipments-for-4Q18-and-for-the-year-overall.393636.0.html