By default, Windows XP uses a mechanism called “pagination”: part of the system resides in memory, the remainder being placed on disk in the form of pages. This mechanism can significantly slow the operation of the system because of frequent exchanges are made with the hard drive to copy part of the system from the RAM or to perform the reverse operation.

If you disable the paging, the core of XP is then permanently in RAM which therefore accelerates Windows. Such manipulation is recommended only if the computer user has 1024 megabytes of memory or more.
1. Perform a full backup of the registry
2. Run Regedit and locate the sub-section HKEY_LOCAL_MACHINE / SYSTEM / CurrentControlSet / Control / Session Manager / Memory Management. Then locate the key, then turn DisablePagingExecutive is updated indicating 1 in the Value data.
3. Close Regedit and restart the computer.

If you have a few optimal functioning of the computer (some programs seem to run out of memory), be sure to restore the registry to its previous state.