If you fix computers, some of my advice might be know to you but I'm just going to throw some suggestions out here.
If you are using:
takeown /f
[folder/filepath] /r /d y
icacls
[folder/filepath] /grant administrators:F /t
to take ownership of the system32 - don't! It can cause many problems down the road.
If your having issues booting from cd, you can try to change it to IDE and not SATA:
Solved Can't Boot from CD-ROM in AHCI mode - Windows 7 Forums (post #5)
Try to DISABLE all others in the boot order, leaving only CD/DVD as number 1.
Check this for more booting from CD issues: (read about the cables and connections).
How to or can't boot from a CD or DVD.
For file permission:
Go to the Properties of the file.
Check if there is a user called "Everyone" with some Special Rights.
If yes, there could be the problem...
Sometimes Windows 7 put following rule:
Everyone Deny to List Folder/Read Data
Just delete this Everyone Deny, press three times ok and that's it.
Follow Microsoft's direction:
Take Ownership of a File or Folder
More detaled and illustrated instructions:
Windows 7 Take Ownership & Grant Permissions to Access Files & Folder