Adjusts various TCP and network settings in Windows to enhance the speed of the Internet connection.

README.md

Most of these settings were mentioned on SpeedGuide.net and MajorGeek.com.

Medium article

Optimize-TCPSettings.ps1

Write-Output "Setting congestion provider to CTCP for Internet."
netsh int tcp set supplemental Internet congestionprovider=ctcp | Out-Null

Write-Output "Enabling Direct Cache Access, and configuring RSS and RSC settings globally."
netsh int tcp set global dca=enabled rss=enabled rsc=disabled | Out-Null

Write-Output "Disabling TCP timestamps globally."
netsh int tcp set global timestamps=disabled | Out-Null

Write-Output "Setting initial Retransmission Timeout (RTO) to 2000 milliseconds globally."
netsh int tcp set global initialRto=2000 | Out-Null

Write-Output "Disabling Non-SACK RTT Resiliency globally."
netsh int tcp set global nonsackrttresiliency=disabled | Out-Null

Write-Output "Setting maximum SYN retransmissions to 2 globally."
netsh int tcp set global maxsynretransmissions=2 | Out-Null

Write-Output "Setting dynamic port range for TCP on IPv4."
netsh int ipv4 set dynamicport tcp start=10000 num=3000 | Out-Null

Write-Output "Setting dynamic port range for TCP on IPv6."
netsh int ipv6 set dynamicport tcp start=10000 num=3000 | Out-Null

Write-Output "Disabling TCP Chimney Offload globally."
Set-NetOffloadGlobalSetting -Chimney Disabled | Out-Null

Write-Output "Enabling Checksum Offload on all network adapters."
Enable-NetAdapterChecksumOffload -Name * | Out-Null

Write-Output "Enabling Receive-Side Scaling on all network adapters."
Enable-NetAdapterRss -Name * | Out-Null

Write-Output "Disabling Receive Segment Coalescing on all network adapters."
Disable-NetAdapterRsc -Name * | Out-Null

Write-Output "Disabling Packet Coalescing Filter globally."
Set-NetOffloadGlobalSetting -PacketCoalescingFilter Disabled | Out-Null

Write-Output "Disabling Large Send Offload on all network adapters."
Disable-NetAdapterLso -Name * | Out-Null

Write-Output "Setting minimum RTO (Retransmission Timeout) to 300 milliseconds for InternetCustom profile."
Set-NetTCPSetting -SettingName InternetCustom -MinRto 300 | Out-Null

Write-Output "Setting Initial Congestion Window size to 10 segments for InternetCustom profile."
Set-NetTCPSetting -SettingName InternetCustom -InitialCongestionWindow 10 | Out-Null

Write-Output "Setting TCP AutoTuningLevel to Normal and disabling ScalingHeuristics for InternetCustom profile."
Set-NetTCPSetting -SettingName InternetCustom -AutoTuningLevelLocal Normal -ScalingHeuristics Disabled | Out-Null

Write-Output "Setting default TTL value in TCP/IP parameters to 64."
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" /t REG_DWORD /v DefaultTTL /d 64 /f | Out-Null

Write-Output "Setting maximum user port number in TCP/IP parameters to 65534."
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" /t REG_DWORD /v MaxUserPort /d 65534 /f | Out-Null

Write-Output "Setting TCP timed wait delay in TCP/IP parameters to 30 seconds."
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" /t REG_DWORD /v TcpTimedWaitDelay /d 30 /f | Out-Null

Write-Output "Disabling non-best effort bandwidth limit in QoS policies."
reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Psched" /t REG_DWORD /v NonBestEffortLimit /d 0 /f | Out-Null

Write-Output "Configuring QoS to not use Network Layer Authentication."
reg add "HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\QoS" /t REG_SZ /v "Do not use NLA" /d 1 /f | Out-Null

Write-Output "Setting system memory management to use a smaller system cache."
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /t REG_DWORD /v LargeSystemCache /d 0 /f | Out-Null

Write-Output "Adjusting LanmanServer parameters for optimized file sharing performance."
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" /t REG_DWORD /v Size /d 3 /f | Out-Null

Write-Output "Setting network throttling index in multimedia system profile to maximum."
reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile" /t REG_DWORD /v NetworkThrottlingIndex /d 4294967295 /f | Out-Null

Write-Output "Setting system responsiveness to maximum in multimedia system profile."
reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile" /T REG_DWORD /v SystemResponsiveness /d 0 /f | Out-Null

Write-Output "Applying NSI registry settings for network performance optimization."
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Nsi\{eb004a03-9b1a-11d4-9123-0050047759bc}\26" /v "00000000" /t REG_BINARY /d "0000000000000000000000000500000000000000000000000000000000000000ff00000000000000" /f | Out-Null
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Nsi\{eb004a03-9b1a-11d4-9123-0050047759bc}\26" /v "04000000" /t REG_BINARY /d "0000000000000000000000000500000000000000000000000000000000000000ff00000000000000" /f | Out-Null
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Nsi\{eb004a03-9b1a-11d4-9123-0050047759bc}\0" /v "0200" /t REG_BINARY /d "0000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000ff000000000000000000000000000000000000000000ff000000000000000000000000000000" /f | Out-Null
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Nsi\{eb004a03-9b1a-11d4-9123-0050047759bc}\0" /v "1700" /t REG_BINARY /d "0000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000ff000000000000000000000000000000000000000000ff000000000000000000000000000000" /f | Out-Null

Write-Output "Setting priority levels for DNS, Hosts, Local, and NetBT services."
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\ServiceProvider" /v "DnsPriority" /t REG_DWORD /d "6" /f | Out-Null
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\ServiceProvider" /v "HostsPriority" /t REG_DWORD /d "5" /f | Out-Null
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\ServiceProvider" /v "LocalPriority" /t REG_DWORD /d "4" /f | Out-Null
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\ServiceProvider" /v "NetbtPriority" /t REG_DWORD /d "7" /f | Out-Null

Write-Output "Setting IRPStackSize for LanmanServer to enhance file sharing capabilities."
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" /t REG_DWORD /v IRPStackSize /d 30 /f | Out-Null