Win8.1 file class registration problem

[Harry Potter]

I recently got a new Win8.1 PC and am having trouble registering files of a type myself. The following is what I have for .cfg:

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Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\.cfg]
@="cfgfile"
"PerceivedType"="text"

[HKEY_CLASSES_ROOT\.cfg\ShellNew]
"command"="c:\\myprgs\\win32\\picker\\tmpcreatwin.exe \"%1\""

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Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\cfgfile]
@="cc65 config file"

[HKEY_CLASSES_ROOT\cfgfile\DefaultIcon]
@="C:\\Icons\\DISK35.ico"

[HKEY_CLASSES_ROOT\cfgfile\shell]

[HKEY_CLASSES_ROOT\cfgfile\shell\open]
@="Open in &Notepad"

[HKEY_CLASSES_ROOT\cfgfile\shell\open\command]
@="\"%SystemRoot%\\System32\\notepad.exe\" \"%1\""

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The problem is that I can't seem to open the file as, when I do so, a dialog box appears saying that I may not have access privileges to the file. The only thing that seems to be missing is the PerceivedType key in the extension key. I want the full functionality but not yet. For now, I just want to use and do operations on these files. Can anybody help me out?