There are all kinds of specific technical answers that you might receive. However, the one general rule that I have found to be true with audio workstation setup is this: some system configurations will work, and some will not work, period.
You are putting together a house of cards made of computer hardware, computer software, audio subsystem architecture, pro audio hardware, pro audio drivers, audio workstation software, plugin architecture, and audio plugins. There are many variables. The pro audio drivers are a specific weak spot.
The advantage that the Mac offers is reduced variables. The computer hardware is less diverse and is welded to the computer software (Mac OS) and audio subsystem (CoreAudio) and plugin architecture (AudioUnits) which are all made by one company. And if you run Logic, that is also from that same company. With Windows, that would be a few different companies. So it is easier for pro audio hardware makers to write great drivers for Mac because for example Apogee can plug a Duet into a Mac running Logic and that is a complete system except for the driver. They can write their driver for that one system configuration and it will likely work on all Macs. Then makers of audio apps all just adapt to work with the same CoreAudio and things continue to work.
Also there are so many pro audio users on the Mac, sometimes the audio drivers are given more work because there are more customers spending more money.
So with your Windows system, you may or may not be able to get it working reliably. And if you do, you may have to become really technically savvy with configuring various versions of all the various parts, which takes a lot of time. You may have to research which driver version goes with which ASIO and so on. But still, your current Windows configuration is not at all as likely to work reliably or as well as your current Mac configuration.
I used to work at a complex with about 100 studios in it, and about 80% were Mac based. There was a guy who made a business out of doing system setup for the Windows users, going from studio to studio solving problems. But even though there were 4 times as many Mac users, there was no corresponding Mac system setup guy because audio engineers setup their own systems and had way fewer problems. All because of having way fewer variables. There was just less to configure and less that could go wrong.
What I recommend is that you spec out the cost of replacing that Windows system with another Mac, and then use that cost as a ceiling for how much time you will spend configuring the Windows system. In other words, if the cost is $1500 and your time is worth $50 an hour, then you can spend up to 30 hours configuring the Windows system before you are losing money compared to buying a second Mac and using it to do 30 hours of audio work for someone else at $50/hour. Otherwise you can get into endless configuration and still perhaps not get a reliable Windows system going. Just figure out when you should pull the rip cord.
What I always recommend to people who are buying a new system is to see the system they are buying already setup and working. A few friends of mine have just cloned my very reliable, always functioning system (MacBook Pro, Apogee, Ableton Live) because that meant basically zero setup and zero risk. Maybe you can find someone with a similar Windows/Focusrite system to yours that is working, and copy the parts you don’t have. Maybe that means swapping out the PC for another or using a different version of Windows or a different ASIO version. But find a working system and clone it shamelessly.
