Yes, with a lot of catching up to do it will take some time. It all depends on the size of the files, and media images are large.

Also, the upload speed from PC to the Internet is typically about one-tenth of the download speed.

Remember just leaving the PC switched on is not enough.

You must be signed-in to your Windows account and signed-in to the OneDrive app too.

Once OneDrive is synchronised, only one file at a time gets changed and synchronised quickly.

But as Victor advised, only run Family Historian on one PC at a time to avoid synch hazards.

Overnight, after a couple of hours, your PC will probably switch itself off as nobody is using it.

(I know it is possible to change the Power Plan to keep it on all night, but that is a bit fiddly.)

So it might be better during the day when you can go back and just move the mouse to keep it awake.

Hover the cursor over the OneDrive cloud icon and it should popup saying how it is progressing.

Don’t forget the Files On-Demand setting I mentioned.

Once syncing has completed you should follow all the FHUG Migration Guide step by step.

You must check the Tools > External File Links as described and use the Backup and Restore Family Historian Settings Plugin.

However, instead of copying the Family Historian Projects folder from PC to laptop, you can just connect the laptop to OneDrive.

But all the other steps are important and don’t forget Ancestral Sources if you use that program

Regards, Mike Tate