I hope someone can give me some advice. My laptop broke last week and for some unknown reason the hard disk had been wiped clean as had my external hard drive and the OneDrive on the laptop.

The computer engineer I use managed to set up the laptop again and downloaded Windows 11 (which doesn't seem very intuitive to use to me, but I guess I'll get used to it). Fortunately, and again I have no idea why, OneDrive back up from 2021 was still there so he downloaded that for me. (Obviously not only did I lose everything on the laptop from 2021, but also anything that I had updated on Legacy since that time - fortunately not too much.
My question is, a few weeks ago I sent a Gedcom Legacy file to one of my grandsons. He downloaded a free Legacy program so he could look at the file. If I ask him to send a Gedcom file back to me, can I load it onto my current Legacy program, or do I need to download another one? As well as my family tree, I also have another tree on the same program connected to my g.grandfather. As I can't find out who his parents are, I haven't linked the two trees yet, but obviously I don't want to lose that family tree which I compiled by researching lots of 2nd to 4th cousins and with their help too.
Any advice would be welcome. Thank you.