Windows Scaling 65535 is the highest value that you can set your Rwin to, without having to use windows scaling. Scaling is needed to enter any number higher than 65535. Most users do not need a higher Rwin that 65535, and so I recommend that this setting be set to default ( off).
Time Stamping This setting may or may not improve performance. If you have a line where latency varies a lot, timestamping may be beneficial.......experiment with it to make sure. I have my setting at default ( off).
Selective Acks This improves the speed of lines that tend to lose packets (packet loss), by re-transmitting only packets that were lost, if any. I have my setting at default ( on).
Path MTU Discovery This automatically sets your MTU to suit the type of line that you have (dial-up or broadband). The highest MTU that you can set is 1500. I have mine set to default ( on).
Black Hole Detection This discovers routers on the web that cause MTU Discovery to work sub-optimally. I have mine set to default ( off).
Max. Duplicate ACKs This allows for faster re-transmission of packets when lost. I leave this setting blank. (blank = 3 for Win98/98SE/ME and blank = 2 for Win2000).
TTL Time To Live is the amount of hops (servers) that a transmission packet will take before all packets are lost. If you were receiving packets from 20 hops away, and youre TTL was set to 19 or less, then all packets would be lost before they reach you. I leave this setting blank (blank = 128 in Win98/98SE/ME/2000).
Adapter Settings This is where you set your MTU. I have mine set to 1500 for both NIC and Dial-up.
ICS Settings If you use Internet Connection Sharing (a Micro$oft program), then you should set the ICS MTU to the same as that of the PC. This is grayed out if ICS is not being used.
When you are happy with your settings, you need to hit the Apply tab (you may need to hit tab to highlight it). Next click on Exit and then reboot the PC. A reboot is necessary to activate the settings.