Unity Webplayer installation error- Unity Webplayer update finished, but installed..

https://forum.unity3d.com/threads/unity-webplayer-installation-error-unity-webplayer-update-finished-but-installed.168840/

I have this issue thats been serious doing my head in.

When I install the latest unity web player, I always get the following error:

Failure to update Unity Web Player.
Unity Web Player update finished, but installed revision (4018001) is less than the required revision (4018002). Please reinstall.

I have searched far and wide and spend about 5 hours time, have seen and followed several threads of users with similar problems, but the solutions, which worked for them, did not work for me.

I have tried the following methods and always the the same error message:
1. Uninstall unity web player. Reinstall web player- didnt work
2. The above + restart computer reinstall web player - didnt work
3. The above + clear browser caches an all browsers installed on os, reinstall web player - didnt work
4. The above + delete all local unity files (all the folders from program files, which remain after installation), reinstall - didnt work
5. The above + download CCleaner and run cleaner and do registry clean, reinstall web player - didnt work
6. The above + use regedit and find every single instance of 'unity' and delete all unity entry files - didnt work
7. Installed the full webplayer .exe file from a .cab file (forum suggestion somewhere) - didnt work
8. Installed the unity editor (forum suggestion somewhere - didnt work
9. Tried clean installing it on firefox, IE9 and Opera.

Im running win 7 SP1, unity webplayer 4.0.1f2 using Firefox.
The webplayer used to work fine back in december (when i last used it here).

I am also located in China, so i wouldnt find it impossible to believe if there was some sort of internet communication problem.
I am a unity developer, in my office i have uninstalled and reinstalled the web player 100's of times, always without problem (just my luck that at home using my free time, i get these issues)
my best guess to the problem is, that somewhere, somehow some old files are stored somewhere (even though i removed all traces on unity) and when it runs the version check, it goes to the wrong directory (or doesnt find it).

any help on this would be great,a s i have literally been yelling at the monitor the whole morning, as this is an extremely frustrating bug.

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Im gonna reply to this thread myself, as I have finally managed to find out the problem (and its a bug, so hope someone from unity is taking note).

Starting by just having uninstalled the unity webplayer (no need for regedits, cclean etc).

First, I install the unity loader.
this creates following folders on my system:

C:\Users\UserNamer\AppData\LocalLow\Unity\WebPlayer\loader

Next, I install the unity webplayer.
this creates the following two folders:

C:\Users\UserNamer\AppData\LocalLow\Unity\WebPlayer\mono
C:\Users\UserNamer\AppData\LocalLow\Unity\WebPlayer\player

Now, for the important bit:

Within each of these folders, there is a file called: 'info.plist' 
If you open up that file with notepad, you can see the string:

<string>4.0.1f2</string>

(Please note, as of writing, the current unity webplayer version is 4.0.1f2, which is shown in the string above. Depending when you read this, your version number may be different)
now, inside of the 'loader' and 'player' folders, the string will have those values,
however inside the 'mono' folder, I have discovered the string to be different.
It shows:

<string>4.0.1f1</string>
not
<string>4.0.1f2</string>

so the version number is different!
I simply changed it so that its the same as the string in the 'player' and 'loader' file and,
it worked!

F***ing knew it all along that there was just some simple verification check at the end, which was causing the cockup.
I spent good 6 hours, researching, following all solutions, even doing system restores. Nothing, but anyway.

I tested this method step by step, repro-ed it about 5 times and it works 100% for my problem (or people who have the same problem as me).

on a final note, i have no idea why the webplayer is creating the bug, i have it running on about 20 systems at the office and no problem. Just for some unknowns reason it happens on my home computer, so i cant clock it off at work :/.

Anyway, if this solution proves useful for anyone, please leave a comment so that others know it works too. 
I don't wish that crazy amount of frustration and troubleshooting for something that should be super simple, onto anyone. 
Thanks!