I built a computer for a my father a few years ago and its had Windows 7 Ultimate on it up until a few weeks ago. When I had first installed Windows 7, the time would randomly change on its own and it drove me crazy trying to figure out what the issue was. The issue hasn't happened in a long time but I can't remember what I did to solve the issue, but now I've upgraded the computer to Windows 10 and the issue has returned. The time keeps changing randomly on its own several times a day. Windows 10 is installed on a new SSD that I added to the computer and the old Windows 7 HDD is in as a secondary drive. Anyone know how to solve this issue? It seems it isn't OS / software related as it only happens on this computer, even with fresh OS install, of a different OS, and on a new drive ...could it be the mobo / Bios time causing the issue?