This post pertains to players using or downloading/installing the newest installer client of March 2011.

If you have,
Completed Windows Updates
Turned Off Your Security Software
Uninstalled / Reinstalled

And you still get the following Error Messages when you try to load your client:

"Fail Execute LastChaos!" > click confirm > "Already Executive Game" > Confirm

Try the following Fix:

(1) Goto Start, Run, and type regedit
Windows 7 Users, press [WindowsKey]+R

(2) Press CTRL+F

(3) Type "aeria" in the search field and hit search

(4) Look for the Registry String Seen Below:

(5) Right Click the Registry String in the right-side window, and hit Delete, click Yes.

(6) Your game should start normally





Experienced Users just navigate to the following registry string

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers

Delete the string containing the binary value "WIN95 DISABLECICERO"

If this string is in your registry, your LC Client will NOT load up.

This issue mainly occurs on Windows 98, ME, NT & XP Editions

Awesome job Andy!

Nice that will help some I'm sure.
<3 Air

Nice finding ^^
Do you know what may cause that string to appear ?
I suppose it's related to user trying to run the game in compatibility mode ?...

I'm under the impression that at one point, a user ran their client in compatibility mode, and it didn't work....and couldn't undo what they did. Uninstalling LC wouldn't have any impact, because LC's uninstaller doesn't look for "other" registry keys that affect itself, other than what it installs in the first place. Hence, when they attempt to reinstall LC, the same string would pick up and keep their client from loading.

So if you have ever ran LC in compatibility mode, and it stop's working, this is why.

Since working with registry will cause a lot of problems(like deleting the wrong key or not finding the key in the registry). So i made this vbs script.

Mod Edit: Removed

How it works
Copy the code below into notepad.

Then double click the vbs file.

Another alternative is this:
Right click on LC.exe ->Proprieties -> Compatibility->UnCheck all


I don't have Lc installed on my pc so i gave example from another application.

Hmm for what is about the VBS script, I'd suggest to look for "\LC.exe" instead of just "LC.exe", just in case the user would have another program of which the executable name ends with LC.exe but is not LC.exe and that needs compatibility mode.
The probability is pretty low, but still it might happen...

Okay it doesn't work for me
I'm using window 7 and I can not fix the problem.
It always says "Last Chaos is allready running on your system" and "Allready executive game"

Have same issue this solution dont seem to work, i am running windows xp

Take a Desktop Screenshot when this error happens and post it up.

You can also try Uninstalling Completely, Running CCleaner, then using the Manual Backup copy.

Naturally, nothing is going to help anyone whom is trying to run more than one client, which is prohibited.