I'll take liberty to shorten your code.
code:
if ingroup("Year6","Year8","Year9","Year10","Year11")
$rs=WriteValue("Software\Microsoft\Windows\CurrentVersion\Internet Settings", "ProxyServer", "", "REG_SZ")
$rs=WriteValue("HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Internet Settings", "ProxyServer", "", "REG_SZ")
$rs=WriteValue("HKEY_LOCAL_MACHINE\Enum\Network\MSTCP\0001\Software\Microsoft\Windows\CurrentVersion\Internet Settings", "ProxyServer", "", "REG_SZ")
endif
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