Blueiris runs fine and everything works as it should but when i enable "Run as a windows service" my PC becomes unresponsive, it takes a min for chrome to open, takes a min to bring up task manger even typing is delayed everything is just sluggish!.

Disable "run as a service" and all runs fine again.

I have tired clean installs of Windows 11 23H2, different passwords and admin accounts nothing seems to help. My CPU runs at 3-4 percent load and GPU at 5 percent it's a Intel i7-12700K with 32 GB of RAM and a NVMe drive.

Any ideas?

Doesn't quite seem right, but I'm wondering if your anti-virus solution is doing this. Can you disable it and test ? It's going to be something weird, and not setting AV exclusions fits that, but then it should affect it when not running as a service too.

Have a look if Reliability History gives any clues.

Yes i have turned windows anti-virus off.

Would a hardware issue cause this? I ask since on another PC Blueirirs will run fine using the same settings, win ver etc.

Makes no sense.

it is possible that it could be a bad memory module etc. Have you done any stress tests on the computer to rule out this possibility!