I have a problem similar to Gerardius's, although in my case PFPX works, but it took more than a minute to launch it, and it's responding very slowly.
Almost every action (creating and compiling a flight, opening any window, saving flight plan, printing OFP, etc.) took about 10 seconds (and even more if my CPU is already busy with running the sim). It feels like I'm trying to run PFPX on a 486 processor.
I've tried it with multiple versions (including the latest 1.28.9i hotfix). I have the latest VC redist packages (including 14.0.24215) and carefully read Tom's troubleshooting FAQ. PFPX was snappy and good on Windows 8.1 and on a earlier versions of Windows 10 (before Fall Creators update, I think). I've tried to reinstall PFXP from scratch a couple of times, and did a clean reinstall of Windows 10 once, but the problem is still here.