More than a few of you have asked this question about Windows 10. “Will all data and programs remain as they are? Hopefully the upgrade will not reformat the hard drive and erase all the data.”
According to Microsoft in almost every case your data should not be affected. All of your programs, games, documents, and pictures should be fine.
However, it is always a good idea to have everything backed up when you’re doing any kind of update or just for safety’s sake in general.