Hello! If you don't mind about your applications and you only want to install Windows 10 keeping your files, then there is another solution. You can boot from a Windows 10 DVD or USB and start Windows Setup. At the partitions screen, do not touch anything! Just choose the larger partition (where usually Windows is) and click Next to proceed. You should see a warning that this partition contains a Windows installation which will be copied to Windows.old folder. Proceed. This way you will have a new Windows 10 installation but all your data will be saved at Windows.old folder where you can copy anything you need and then clean up the disk to delete anything else. Of course you will need a valid Windows 7 or 10 license to go that way and you will have to reinstall any application.

To avoid reinstalling everything and keeping your data, you have to go Vista->7->10 you cannot go from Vista directly to 10. You will need the same language and architecture (32-bit or 64-bit) as the Vista to allow you to upgrade. Also you can go from Vista Home to Windows 7/10 Home or Pro, but if you have Vista Business or Vista Ultimate you can only go to 7/10 Pro.