It's been awhile since I've done and I have another laptop to upgrade. Does the current version of the upgrade wipe programs and data, or will that stuff remain intact?
You can wipe the programs but keep the data, wipe everything, or keep everything. The tool will default to what it thinks you want, but you can change it.
The only problem I've run into was upgrading my old work computer; i7 processor and lots of RAM, it easily supports W10 but it's not on the company's list of supported models. I wanted to keep it as a "work from home" workstation rather than turn it in and having it scrapped, so I upgraded it myself. That went okay, but when I connected to the network they detected it and scanned it and found out I didn't have "secure boot" enabled (that's a new corporate requirement for 10) I went into the BIOS and enabled secure boot, then by HDD wouldn't boot anymore. Not sure if the thumbdrive thing that Calumus mentioned would have worked or not. I got some install media from one of our technical sales support guys and did a clean install from that.