Some of the tweaks used in Windows98 are no longer relevant in Windows XP.

VCACHE

Windows XP file I/O is more efficient than Win9X, so the VCACHE tweak used in Windows 98 is not needed in XP. Just make sure that the discs are regularly formatted and use either FAT32 with 32KB clusters or NTFS with 64KB clusters (audio disc).

ConservativeSwapFileUsage=1

This line goes  into the system.ini file on Windows 98 and ME, after the [386 Enh] tag, and makes the OS use the RAM more than the swap file on the disc. 

However, this has absolutely no effect in Windows XP, so it is not necessary. Try putting it in and checking your PF usage in the performance section of your task manager. It makes no difference at all.

This setting has different meanings depending on which version of Win9x you are using. It wasn't even introduced as a setting until Windows 98 came out, so don't bother with this one if you are still running Win95. If you are running Win98 or 98SE, this setting will force the computer to use the swap file in a "conservative" way, which in other words is the same way as Windows 95 did. If you are running on Windows Me (this is one of the big speed tweaks for WinMe, particularly if you have more than 128 Mb of RAM), this setting will tell Windows not to use the swapfile at all until all of the RAM is used. After all of the RAM is used, the computer will push off the most infrequently used data to the swap file. This setting goes under the [386Enh] section.

Graphics Card Colour Setting

It is not advisable to use 256 bit colour depth. Stick to the default setting. Modern graphics cards tend to be optimised for 32 bit, which means that 16 and 24 bit are also not recommended. If you're having problems at 32 bit try lowering to 24 or 16 bit, etc.

If you think you are having problems relating to your graphics card, try downloading the latest drivers from the relevant manufacturers website. If this doesn't solve the problem, then try reducing the colour depth to 16 or 24 bit instead of 32 bit.