I see, you're doing everything locally.
You won't need to change the permissions on the file(s) because xampp (apache) is running as a system service on Windows and therefore has system privileges. You should continue with your installation and see if any errors are thrown.
If you're making an OS, why are you using Microsoft libs?
If it took you 6 months to make just this portion of it, how long do you think it would take you to create a proper kernel + OS?
How did you come to 35% for PHP? And 55% for JavaScript? Proper way is to show samples of what you've done. Not estimate on your knowledge. That would baffle potential employers.
I need someone to create me a logo that says 'ChromeHost'
PM me for further details. I will require a few mock ups. You will be compensated for your work.