Windows 7 - Hidden System files are no longer hidden

Some of my important system files are no longer hidden and I can't hide them even with the Command Prompt "attrib" command. Files such as bootmgr and ntldr are shown and I can't hide them. Also, show Protected System files is unchecked and show hidden files is also unchecked so they shouldn't be showing. I tried to re-add their system file attribute but I keep getting an "Access Denied" error in CMD and I do not have user account control on and I'm on a Default Administrator Account. Please Help...

Welcome to Seven Forums hpardo.
Have the files recently become unhidden? Maybe you installed a new program which fouled up your file system. Run this tool to correct corrupt files, it won't change your personal files. SFC /SCANNOW Command - System File Checker

Yes I did in fact do something to make them unhidden forever by accident (Only wanted to hide them OSX too). I dual boot Mac OS X 10.6.8 Snow Leopard and Windows 7. While in OSX I can still access my Windows 7 Hard Disk but my system files showed up as visible in OSX so I used a program to hide them. Then, when I tried to start Windows it said the files were missing so I booted OSX and unhid the files and Windows booted like normal again. I know what I did, I just want to know if anyone can help me hide them again just incase something happens and I don't like seeing them there. I can't hide most of the files only some (e.g. Boot folder).

See here: Hidden Files and Folders - Show or Hide