I think that a 'clean' install would better. Installing XP over the top of
itself may not solve your PC problems. Have a look at the following article
by MVP Michael Stevens - it will take you through the steps of a 'clean'
install. Don't forget to backup your data files first:
The downside is that whatever caused you to repair-install may survive
the process and continue bothering you. The plus side is that it keeps
your data. If you back up your data you could perform a clean install,
which begins truly anew.