You could type sfc.exe in start>run and this will bring up the system file checker.Click scan for altered files and it will go through your system in forming you of system files that have altered ,are corrupted or have been deleted.It should tell you that pstores.exe has been deleted and offer you the choice of restoring the original from cab files or from disk.You can choose the cab files to restore from.You may see lots of files changed , altered deleted etc but just restore the one you deleted (pstores.exe),and dont worry about any others tha SFC may throw up.Failing that i can always send you the file as i use 98se too.
me