Although Windows 10 is a great upgrade for many people (especially those who have suffered through Windows 8 or 8.1), Microsoft made a change that will affect athletes using any Polar heart rate monitor (such as the RS800CX) that uses the Polar USB IrDA Adapter. The adapter is used with Polar software running on a PC to configure the heart rate monitor (e.g., training zones, workouts, clock, etc.) and to download workout sessions.
How do I know? I upgraded by home PC to Windows 10, and I no longer can sync by Polar RS800CX with my PC.
This gets a little technical... Microsoft removed the IrDA stack from the final version of Windows 10. Before Windows 10, IrDA devices worked, like the Polar USB IrDA Adapter, without any special driver. Now vendors must provide a complete driver for their products that have IrDA features. Polar announced they will not provide a Windows 10 driver for the Polar USB IrDA Adapter. This means if you upgrade your PC to Windows 10, you will no longer be able to program workouts, change settings, or download workouts.
Polar RS800CX heart rate monitor and Polar USB IrDA Adapter
One enterprising individual was able to bypass the problem by installing VMware Player and creating a Windows 7 virtual machine running under Windows 10. He says, "It did take some hours to read, research, install VMware, install Windows 7and install the software and drivers. Once installed though, I find it very easy to use. One tip: When everything is installed be sure to plug in your IRDA USB device prior to starting the Virtual Machine so it will be recognized." So if you're an IT professional, go for it: see VMware User Manual pdf and VMware Player Download.
For the rest of us, you can postpone upgrading to Windows 10 or buy a new heart rate monitor. Polar "encourages you to shift over to our new Flow compatible products for full product support." Thanks Polar.