Thread: Windows 7 Environment Variables out of sync

I am having a very weird issue with Windows 7, and I'd like ideas. I appear to be having some sort of sync issue with my environment variables.
So I recently changed from Apache Maven 3.0.5 to 3.0.3 (work required it).
The previous maven folder was located at:
C:\...\apache-maven-3.0.5
The new one is located in the same place, and 3.0.5 version was deleted:
C:\...\apache-maven-3.0.3

Maven requires 2 environment variables to be set: a M2_HOME variable, and then an added PATH variable: M2_HOME\bin
I adjusted my M2_HOME variable accordingly, and left the PATH variable alone, since it is just referencing the M2_HOME.

Ok, so when I log into my computer, if I open a command prompt and type:
mvn -version
I get the standard:
'mvn' is not recognized as an internal or external command, operable program or batch file.
If I then type:
echo %M2_HOME%
It replies with the new correct directory:
C:\...\apache-maven-3.0.3
If I then check my PATH variable:
echo %PATH%
It prints (among the rest of the paths) the OLD and non-existent maven folder:
C:\...\apache-maven-3.0.5\bin

And as if that all wasn't weird enough, to "fix" the problem, all I have to do is go to my environment variables, open the edit for the PATH variable, and then immediately close it without changing or saving anything. After I do that, my echo of the PATH variable is suddenly correct:
C:\...\apache-maven-3.0.3\bin
And everything works properly.

Another solution is opening up the command prompt in Administrator mode. If I do an echo of the PATH variable then, I get the correct variable:
C:\...\apache-maven-3.0.3\bin
If I then open the command prompt normally (not in Admin mode), it is still in its "broken" state.

To revert the PATH variable back to its broken state, all I have to do is log out of my account, and then log back in (no need to even turn the pc off, just logging out does it).

Does anyone have a clue what the heck is going on here?

I found the problem. The registry values had not updated with the new path. So every time I logged in, the system variables were loaded from the registry, which had the wrong values. When I opened the edit environmental variables window, the currently loaded values in memory were updated to reflect what was in the window.
That's why the problem came back on startup and why simply opening that window solved the problem.