How to disable RC4 in Windows 2012?

RC4 is not disabled by default in Server 2012 R2. It only has "the functionality to restrict the use of RC4" build in. You will have to set the required registry keys by your own:

The RC4 cipher can be completely disabled on Windows platforms by setting the "Enabled" (REG_DWORD) entry to value 00000000 in the following registry locations: • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\RC4 128/128 • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\RC4 40/128 • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Ciphers\RC4 56/128

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