An easy way to solve this problem, do a fresh installation of XP like clegaw said, try xp sp2, and almost with sure you`ll not have more this problem, one more thing when you go to do the installation:
When you run the xp setup program using the cd, you can manipulate your partitions at your disk, do two primary partitions - C:/ and D:/, your important files stays at d:/ and your system what is instable stays at c:/, what you can format and reinstall your programs without loose your important files, one more thing, xp sp2 has an important security agent to keep your computer safe, the xp firewall too can help, you don`t need to have an antivirus running all the time and spend more memory and processor but if you feel safe with it, keep it, i prefer to use the online symantech checker. Try to uninstall your current protections programs, like antivirus and spyware removal tools and install them again. Pagefile.sys is your swap file and is high, see if your memory isn`t with problems and if all memory you have the system can see it.
