This setting enables you to specify if your system cache should allocate memory for a desktop computer or network server purpose, because a network server needs more space file caching and a desktop computer needs more space for running software applications.

If you use this setting, Windows XP will be forced to take all the system memory and use it for the file system cache. So this setting gives the operating system more possibilities to react, so that the computer can cache the operating system for memory. If your computer needs more than 4MB, he can get up to 8Mb according to his needed purpose, because 8MB is the available RAM for this.

NOTE:
Microsoft recommends you to disable this setting for Microsoft SQL servers, Microsoft Exchange server and Internet Information Services. These applications can also override this value in the case of an installation. You can test this by starting an application that needs lots memory.

value of LargeSystemCache:
0 --> system cache for desktop computers
1 --> system cache for network servers

For this, go to Start > Run menu, enter “regedit” and navigate to the registry path listed below. You can create a DWORD value “LargeSystemCache”, if this value does not exist.

Now, right-click and modify the value to “1” which can optimize the system cache size. However, if you want to get back to the original state, change the value to “0”.