accidentally deleted files-borrado accidental de ficheros del sist

(ingles-español)I´m using windows xp home edition version 5.1 and I must have
deleted some important files, I don´t even know the number or names of them,
but now some programs like Outlook are not working, neither I can install
games etc. My question is: Is there a way of searching through my sistem to
find out what files are missing and install them back? Apreciate your help!
Soy usuario de windows xp home edition version 5.1 he borrado por error unos
archivos del sistema,pero no se el número de ellos ni su nombre,quisiera
saber si existe alguna manera de analizar mis sistema para saber cuales son y
reponerlos? muchas gracias de antemano!