That's in fact what the new operating system was designed for: A brand new, clean install. For those who actually have a working and stable PC/Windows 7 or 8.1 configuration - and especially those who depend on it for their livings - the recommendation should be: wait as long as you can to upgrade. If you want to play with Windows 10, try upgrading your Microsoft Surface Pro tablet or just buy one of those latest touch-screen convertible laptop/tablets and start exploring.
Looking at the recent announcements from Intel, the computer industry in general, or the latest trends in mobile computing and devices, it is clear that Windows 10 is a unique opportunity for Microsoft to have a clean restart, benefiting from a new generation of devices that we will start to see around the end of this year. In my opinion, Windows 10 was designed for those new machines.
If you really have to, or have the time and the patience to start "tweaking" your existing PC, be prepared to face the pain of fixing issues, bugs, and problems. And I don't even need to discuss hardware problems in general. We can just focus on audio.
Even though many software and hardware companies have been following the beta evolution of Windows 10 for months, it is clear this transition is an important challenge and that's why many are not ready, especially from the hardware/drivers side. If you upgrade an existing Windows 7/8.1 machine to Microsoft's latest OS, you are going to need to reinstall drivers (if they are available) for your sound card or audio interface. And whatever configuration you have, remember: you will have to go through a complete reconfiguration of your system's device settings - assuming the devices will be recognized.
According to Microsoft, Windows 10 introduces major technology upgrades in terms of both audio and MIDI with new features and API's available for all Windows 10 supported platforms (remember, that includes desktop PCs, laptops, tablets, and Windows Phones). There are new MIDI API's with multi-client support, the promise of an improved audio stack performance, and new audio processing configuration options reducing audio latency, depending on the hardware. There's even native support for new codecs such as FLAC and ALAC and web-based audio support on Microsoft's new browser, Microsoft Edge.
But as I said, the most important changes will come in the near future, with the help of new hardware to support things such as USB 3.1 and USB Type-C, Thunderbolt 3, Bluetooth MIDI, and so forth.
And that's - in great part - the reason why most audio companies have not announced Windows 10 support as quickly as some might have expected. In fact, most pro-audio/DAW companies are struggling with basic upgrade support for the reasons noted. Steinberg, for instance, is not advising its Cubase and Nuendo users to upgrade to Windows 10 just yet. One of the reasons is the latest QuickTime 7.7.7 cannot be installed on a Windows 10 system, which basically removes the video support in Cubase and Nuendo. Also, most hardware configurations are showing serious compatibility issues because USB and Firewire drivers are still not available.
Among the more active companies - mainly those with less problems of legacy code - there are some examples of Windows 10 support confirmations, but mainly for the most recent software releases (e.g., Cakewalk's SONAR and Presonus' Studio One 3) running on relatively recent hardware. Without exception, all those companies are basically advising users to keep checking the certification announcements, back up their systems, and be patient.