By default, the maximuym transmission unit (MTU) used by Win95 to determine TCP packet fram length is 1,500, which works will if you're connecteding to the Internet through a LAN, but can slow down you connection through a modem. Since many ISP routers use a MTU of 576, your packets can become fragmented as they pass through the routers. This will slow down your connection.
Win98 addresses this by allowing the user adjustment of the TCP packet size throught the Network Control Panel, but Win95 user need to hack the Registry to make these adjustment. The MTU setting is located in one of the 000x keys stored in Hkey_Local_machine\Systme\CurrnetControlSet\Services\Classes\NetTrans. The key you need to edit will contain a DriverDesc string labeling it as TCP/IP. Add to this key a new string labeled MaxMTU containing the value 576. Before you restart your machine to implement the change, open up the VxD\MSTCP key located in the same Services subtree and add a new string labeled DefaultRcvWindows and give it a value of 2144. This value is derived by the formula (MTU-40)x4.
After you reboot, you should notice a speed increase in your Internet connections; how much of an increase depends upon how your connection is routed. The values provided her are the lowest common denominator for ISP routers. Your ISP may use different settings, so it's worth experimenting with these settings to find the perfect fit.