Can an ex-boss take back a gift that was given while employed?

When I first started my previous job, I was using my personal computer at work. It became unusable after about a year. My boss bought me a computer to replace it and set it up in my name. I left that job in December of 2015. He had one of his employees contact me in January 2017 to let me know that he wants the computer back to give another new employee. Can he do this?