In Regedit search for "taskmgr.exe" is the easy way, then you don't get all the other entries for taskmgr.
1st is KLM\SYSTEM\Controlset001\Control\Nls\MUILanguages\RCV2\Taskmgr.exe
2nd is KLM\SYSTEM\Controlset003\Control\Nls\MUILanguages\RCV2\Taskmgr.exe
3rd is KLM\SYSTEM\Controlset004\Control\Nls\MUILanguages\RCV2\Taskmgr.exe
4th is HKLM\SYSTEM\Controlset\Control\Nls\MUILanguages\RCV2\Taskmgr.exe
There are 4 on this PC the number of entries seems to vary. The Binary value to change is the one beginning with 52 04. Its number 0 on my PC. when you double click it you will see the last 28 0A in the third and fourth columns is the wrong way round compared to the others. Hope this helps R.