At home we upgraded two Windows 7 desktop PCs and a Windows 7 laptop. In each case most of our existing programs survived the transition to Windows 10 and kept working. BUT, in each case there were one or two programs which were lost/deleted. Other than one very old program from early Windows XP, we were able to reinstall the missing software after updating to Windows 10.
One other thought, here. Once you've successfully updated to Windows 10 you may, if you wish, do a completely "fresh" install of Windows 10 with no trace of Windows 7 remaining. Your Win 10 "validation" key or number is stored online so you don't need to enter any numbers usually. Some users report this provides a smoother, glitch-free Windows 10. We had no such problems on ours, but i thought it worth mentioning.
A friend of mine who never throws anything away decided to have the best of both worlds (in his humble opinion). He cloned his Windows 7 onto a different hard drive of the same size/capacity and confirmed that the cloned version worked OK. Then he upgraded to Windows 10 on one of the hard drives, and he disconnected the other hard drive (the one with Windows 7 intact and working). To be clear, he left that hard drive physically installed in the PC case and unplugged the data and power cables from the end of the hard drive. Thus, if he ever wants to go back to Win 7, he can plug it in and enable it as the main boot drive in his BIOS setup screen.