Developer tools getting disabled

UPDATE:

I've made a small video with step by step instructions.


1 - Close Chrome
2 - Open the file:

C:\users\[your users account]\AppData\Local\Google\Chrome\User Data\Default\Preferences

3 - SEARCH FOR:

"devtools": {
something...
"disabled": true,
something...
},

4 - CHANGE TO:

"devtools": {
something...
"disabled": false,
something...
},

5 - Restart Chrome.


DISABLED: enter image description here

ENABLED:

enter image description here

TIPS
1 - If you cannot find "disabled": true, just add the value "disabled": false, under devtools. 2 - You may want to copy the contents of the file to http://jsonlint.com/ in order to read properly.
3 - Backup the Original file (just in case)
4 - I've tested enabling and disabling devtools and it works as expected.
5 - If the problem persists, you may want to disable your extensions in order to ensure they aren't messing with your preferences. The same applies to antivirus.


UPDATE

You said:

notepad ++ complaints saying the source file has been modified by another program

It doesn't matter, other values may have changed on the file, and that's normal, but the values you've added won't change.


Try deleting this folder:

[user drive]\Users\%user%\AppData\Roaming\Google

which I got from a Superuser question.


Or, do:

Press the Windows key + R, type regedit.exe and press Enter HKEY_USERS\ -> S-1-5-21-1177238915-1897051121-839522115-1003\ -> Software\ -> Microsoft\ -> Windows\ -> CurrentVersion\ -> Group Policy Objects\ -> {91DD4E7D-FE0F-4B62-A092-91DC1486888E}User\ -> Software\ -> Policies\ -> Google\ -> Chrome

Delete the ones in RED. Click on "Google" and click on "Edit" and select "Delete". Click on "File" and then "Exit".

Did it work?