Windows 10 came available this week. Off I went and upgraded (did not do a fresh install!) Windows 7 to the latest operating system from Microsoft. During the installation I thought GRUB would not be there anymore. That didn't happen. When PC booted again, GRUB was the first one to greet me.
Keep in mind my PC has so called "old school" BIOS (not UEFI). Dual-boot still works and I'm grateful for that. For example installing Linux-based mobile operating systems on my Nexus phone is IMHO so much easier via Linux. That's why dual-boot is so important for me.
Upgrading from Windows 7 to Windows 10