Is Windows 10 Rollback safe?

I roll back my wifes pc because she thought she should upgrade without me present which resulted in her loosing all her data. I did a roll back(took less than 5 min) and all was like before.

if u still have the Windows.old folder i think there are no problems to rollback

I did the same, no problems at all.

Don't you mean downgraded to windows 10?

Sorry, I can't help you. My system was a fresh install.

It worked perfectly. Thanks for your comments, confirming this would be a safe process :)

I rolled back after a few days because of issues with my USB 3.0 ports and I did end up having a few lingering issues. The worst one being corrupt Task Scheduler entries. I had to reinstall many of my programs that had their own updating system because they quit receiving updates due to the corrupt entries. The more things that you change in Windows 10 the more problems you may have if you decide later to roll back. This seems to be a common issue that many others are reporting now that they have had some time working with the new OS.

My upgade failed and it reverted back to 7, windows was so badly corrupted i had to do a reinstall.

I did a "refresh" while on windows 10 and after it rebooted I got a boot device error and couldn't get around it. I tried all sorts of stuff in the bios like changing drive to IDE, but I came to the ultimate conclusion that windows 10 had bricked my computer. Fortunately windows 8.1 installed fine from my backup cd. I'm going to give it a few months before I upgrade again. That said, I kind of liked windows 10 and had no real issues until that particular situation. I still prefer windows 8.1 with Start8 though.