Check that a Group Policy is not effecting your ability to modify connection settings:
Start, Run, gpedit.msc
Expand:
User Configuration / Administrative Templates / Network / Network Connections
Normally none of these settings are configured.
2. Disable the setting using .reg or .cmd file through the logon script or an Internet Explorer desktop shortcut
A. Regedit Method
Copy/paste the below and save as a text file called no_auto.reg
-----begin copy/paste below this line
REGEDIT4
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable"=dword:00000000
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings"=hex:3c,00,00,00,ad,5b,00,00,01,00,00,00,11,00,00,00,32,\
00,30,2e,35,36,2e,32,32,35,2e,31,33,38,3a,38,30,00,00,00,00,00,00,00,00,01,\
00,00,00,00,00,00,00,50,52,fd,5d,d6,5f,c5,01,04,00,00,00,00,01,00,06,c0,a8,\
28,64,c0,a8,ee,01,c0,a8,40,01,00,00,00,00,00,00,00,00
"DefaultConnectionSettings"=hex:3c,00,00,00,ab,3d,00,00,01,00,00,00,11,00,00,\
00,32,30,30,2e,35,36,2e,32,32,35,2e,31,33,38,3a,38,30,00,00,00,00,00,00,00,\
00,01,00,00,00,00,00,00,00,50,52,fd,5d,d6,5f,c5,01,04,00,00,00,00,01,00,06,\
c0,a8,28,64,c0,a8,ee,01,c0,a8,40,01,00,00,00,00,00,00,00,00
------- end copy/paste above this line
B. Same thing as a .CMD file:
------ copy/paste below and save as a text file no_auto.cmd
rem uncheck "Automatically detect settings"
reg delete "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections" /v SavedLegacySettings /f
set SLSKey="3c000000ad5b000001000000110000003230302e35362e3232352e3133383a3830000000000000000001000000000000005052fd5dd65fc5010400000000010006c0a82864c0a8ee01c0a840010000000000000000"
reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections" /v SavedLegacySettings /t REG_BINARY /d %SLSkey%
reg delete "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections" /v DefaultConnectionSettings /f
Set DCSKey="3c000000ab3d000001000000110000003230302e35362e3232352e3133383a3830000000000000000001000000000000005052fd5dd65fc5010400000000010006c0a82864c0a8ee01c0a840010000000000000000"
reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections" /v DefaultConnectionSettings /t REG_BINARY /d %DCSkey%
--------- end copy/paste for no_auto.cmd