I’m running Cubase Pro 15 on a PC using Windows 11, Norton 360, and Windows Defender
What processes should I disable on them for the DAW to run with the lower amount of CPU spikes?
If it was me I would get rid of anything Norton, Defender is all you need IMHO
Agreed…at least check how it performs if you simply turn off the realtime Norton protection. Aside from that, it’s not usually as simple as disabling a few processes to solve cpu spiking (usually dpc latency spiking). Though I personally would always disable usb power management if using usb audio (selective suspend in windows power settings and in device manager/usb hubs/properties untick allow computer to turn off this device to save power)
Once bitten…Twice shy. I’ve experienced identity thief once 26 years ago. Don’t want to go through that again. 
Me as well. I’ve had my bank emptied.
There’s lots of things that you could disable, and also lots of things that disabling will break your computer. It’s a bigger topic than just a simple comment.
I don’t have windows 11, but with windows 10 there are so many microsoft things, and others that I’ve bricked and it still works fine. But I’m not sure you can manage programs and processes with norton. You might need stronger medicine.
A few onboard things to look at (not sure about win 11 though) is group policy editor, task scheduler, services, and even the windows firewall (but not the firewall for microsoft things. Don’t try and make microsoft mitigate its own software. It’s not like they will let us use their own software against them. Use a third party for that.)
I’d forget processes or services and concentrate more on the power plan, and maybe turn off the power saving functions in the BIOS.
…unless to journey into the murkier places in the darker web…
Uninstall Norton, disable OneDrive, use Studio drivers for your graphics card, assuming it’s a desktop if the motherboard has wifi disable it in BIOS(unless you connect that way- not something I’d recommend).
If you’re serious about audio don’t play games, surf around, use email, etc. I use internet on my DAW for audio program and plugin updates only.
As for security, times have changed…now it’s state sponsored(Russia, China, Iran, North Korea, etc) hacking groups that don’t want to get into your machine…they get that information from your bank, your hospital, etc. Hacking is big business now and until countries decide to act it’s not going to change unfortunately
The vast majority of services/processes aren’t doing anything unless triggered. For the most part, you don’t need to disable anything. There are more services as we move things out of the kernel and into user space, or we break apart monolithic features into more discrete units. That doesn’t mean more “stuff” is happening, it just means the code is running in a different place now.
- Set your power to “Best Performance” using the Windows Settings app, not the old control panel.
- If using Defender, exclude your Cubase working folders (and, if you are not downloading random VSTs, the Cubase process itself) from real-time scanning.
- As said by others, don’t use a OneDrive-managed folder as your working folder for projects.
- If you have any gamer optimizers (network, graphics, RGB lighting, etc.) I recommend removing/uninstalling them.
- If you have a branded PC, like Dell, you probably want to remove all or almost all of their services that check for updates “health” etc.
- If you are using Chrome as a browser, understand that it installs a bunch of regularly scheduled tasks for update checking, and annoyingly if you aren’t using Chrome as your primary browser, displaying toast messages extolling the virtues of using Chrome. That’s something I found last month. Pete Brown @ Microsoft::Windows on X: "Starting to see a bunch of these. Anyone know what pops these up? I have two of the three Google background services disabled. I don't use Chrome except for testing once every few months, so not running. No, these are not from web sites so search/AI comes up unhelpful. https://t.co/tHwprUMysA" / X
Anything else is going to be VERY system-specific. There are huge tweak lists out there that cause as much harm as good, and make people think you have to massively customize a Windows system to use it for audio. In most cases, if you started with decent hardware to begin with, you don’t. Most of the rest is about getting every ounce of performance out of the PC, and that becomes the hobby vs making music. Fine for overclockers and system builders.
Oh, and despite it being shared around everywhere, never set your system to prioritize background services. That’s opposite of what folks here need.
I wrote a series of blog posts about this a few years back. It still applies. Unofficial Windows 10 Audio Workstation build and tweak guide - Part 1 - Windows MIDI and Music dev
Pete
Microsoft
Can’t agree more i go one step further I even disabled gpo for defender since 95% i dont go online my daw workstation is for daw purposes work well until the latest update which I seem to have fixed 
love windows 11
You also have to periodically re-check those disabled services as Microsoft sometimes will re-enable them following system updates.
Correct. Disabled in-box services are often seen as “broken” and so get fixed on any major upgrade/update. The deployment system (correctly) doesn’t see these things as a user preference, but a broken system, just like if system files were removed.
That’s why repair and the sfc/scannow etc. stuff people do can work to fix a system.
If someone is hell-bent on disabling in-box services, the best approach is to store all that info in a PowerShell script, and then re-run that after a major update/upgrade to ensure the services are still disabled.
Pete
Microsoft
“As for security, times have changed…now it’s state sponsored(Russia, China, Iran, North Korea, etc) hacking groups”
Please add Venezuela and Cuba to the list. I mean why not, right? That depends on BBC news, of course.
And the UK and the USA!
They’re only saving the poor children…in their own words.
Thats the main reason I avoid them.. its a pain to keep changing power settings in device manager..
I had issues with stability and disabled Nahimic in Services.
It is documented as potentially causing issues, and Fabio from Steinberg was helpful in advising me to disable it.
It can also help to go around Windows settings and disable a whole bunch of useless features such as gaming bars, a Google search will keep you busy tweaking for a bit.
I also disabled my Killer Network services and that seemed to help (I did get a series of Cubase crashes and even a major OS crash so I’ve been through all kinds of stuff)
Final stuff, NVIDIA cards and dual screen setups, having the latest driver may not be what is best as an older card could cause problems with new drivers. An AI search helped me revert to an older driver for more stability…
Basically, it’s all dark arts …
Gaming network accelerators, like Killer, are top on my list of things that cause massive DPC latency issues.
On the plus side, they aren’t all that common anymore, compared to 10 years ago.
Pete
Microsoft