Tweaking Part 3 - The Registry
There are many settings that can be entered or changed manually in the registry, some of which are those that have disappeared since previous driver versions. The registry can be edited using inbuilt Windows tools, namely regedit.exe or Regedt32.exe.
The location of the registry keys that need to be changed depends on your particular operating system:
Win9x\ME: "HKEY_LOCAL_MACHINE\Software\NVIDIA Corporation"
Win2000: "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ nv4\"
WinXP: The exact key varies from system to system, but there should be a general key "HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET001\CONTROL\VIDEO\nice long hex string\0000".
If you have had a few different video cards in your system there will be several possibilities for the "hex string", just find the one that mentions your current card in the "Device Description" value. Some of the various registry values that can be added or modified are:
EnableVia4X - Forces the AGP mode to 4X for VIA chipset based systems. This has the same effect as installing the 4-in-1 AGP drivers in Turbo mode. It is a hexadecimal value, having values of 0 or 1 (off or on). Setting 1 will turn this feature on.
EnableAGPFW - Forces AGP Fast Writes, as long as it is enabled in the BIOS. 0 for off, 1 for on.
Coolbits - Enables the clock frequency adjustment tab in the reference drivers for core and memory frequency adjustments.
Device Description - Change this in the right location (I'm not going to tell you exactly because that would make it too easy) can really impress your mates by making your Geforce2 MX200 show up as a Geforce4 Ti 4600. Of course there will be absolutely no performance boost except for an increased ego!
Whilst you can modify all of the values yourself, it is much easier to use a utility such as the GeForce Tweak Utility to do the hard work for you. It also supports reverting to original settings and some presets so that you can tweak settings for particular applications. Most of the settings that it supplies don't impact frame rates in a positive way, they generally increase stability and/or solve compatibility issues with certain hardware combinations. The main things you can use it for are to add the coolbits overclocking tab and the couple of other settings mentioned. It saves directly editing the registry yourself, avoiding possible mistakes.