I have version 10 installed on a Windows 7 64 bit machine.
It works but I wouldn't want to use it as there are problems.
But it should be good enough for you to open and save your old job.
However 10 will only open files back to 6.5.
So if you do have a 6.0 file then you will need 9 or before.
There are file converters here that will run on your machine.
Version 9 is there.
http://www.graphisoft.com/downloads/fileconverter.html
They don't need to be installed - just download and extract.
Barry.
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11