It seems to me that he's running games. In a console cabinet. Which means he's probably running one of those book sized machines.Yes, on a system with 16GB of memory (as it seems) and a quad-core, if that won't perform properly, what else will?... As said, I think he's hunting for ghosts. Overclocking, or selecting a higher frequency CPU, will add more bang than running Win PE with all it's limitations.
Even on a 16 GB machine, windows processes can interfere and make your gaming experience less than optimal. If he can get this out of the way as a possible impediment, and then move on to doing things with the hardware if necessary, I'd see it as a useful step, personally.
And that is more often caused by I/O interrupts that make the processor "hick-up". A reason is usually a sub-optimal hardware mix, no matter how over provisioned.
If an absolute bare-bones Windows installation is what you after, you should look at how musicians set up their Windows-based studio. Those persons have a much better understanding of what hardware combinations work and all the services/functionality you must strip from Windows that create these processor "hick-ups". Normally you barely notice interruptions in the flow of information that your eyes/ears receive from the computer, but when the soul purpose is to record the best quality sound without any interruption from either hardware or software, you install only the bare minimum of extra software and strip all surplus from that computer.
Persons that have such a computer usually keep it out of any network, disable all Windows updates and won't patch any software unless absolutely necessary, as such a state is difficult and often expensive to attain.
Which is why it is often easier to not use Windows. A Raspberry Pi computer is much more limited in hardware capabilities, but it is hardware that has proven to work very well together. Then there are special Linux-based operating systems for it. Hardware and software that work in tandem.
After taking a brief look at Launchbox and Kalla, my personal preference would be Kalla, because of its cleaner, deceivingly simpler look. While Launchbox appears to have more expansion options, Kalla works with PC's, Mac's and raspberry Pi or similar devices. If looked at pure gaming experience, I think both systems are pretty evenly matched.
Hirens BootCD is under new management and made a new PE disc based on Windows 10. This can be easily adjusted to your needs. I created a bootable pendrive, then added my whole portable apps collection to it (about 12GByte) and 70% of those worked right out of the gate. With looking/applying missing dependencies that is now up to 90%. Just to indicate that adding, but also removing tools/apps, is quite simple with this boot CD. The Hirens BootCD is also only half the size (1.3GByte) than the Bob.Omb's Modified Win10PE boot CD (2.6GByte), while both have very similar feature sets and functionality.