|"I would just run a Repair of XP.."|
Running what many call a Repair install of Windows (I prefer to call it a Repair Setup, because what it does is run Setup again without deleting the contents of the existing partition Windows was installed on) takes a little less time than Windows Setup originally did to run (less than a hour or so), but you must have a regular Windows CD or the equivalent to run it (you may not be able to run it from the CD(s) that came (come) with a brand name system, if it came with any), and an XP Repair Setup (Repair install) will (almost always) not harm your existing Windows installation, but it can only fix things Windows detects as wrong, and/or replace corrupted or missing Windows files that are on your original XP CD.
It can't fix things that are caused by things that are not on the Windows CD, it can't replace missing files that are not on the CD that have been deleted on the computer, or fix/replace corrupted or missing files that are not on the Windows CD, and it can't fix problems caused by you installing the wrong software or buggy software or installing software the wrong way, if it wasn't on the Windows CD.
If for your own curiosity you want to know how you do that...
How to do an XP Repair Setup (Repair install) , step by step:
In order to run a Repair Setup (Repair install), you need the Product Key, preferably the one that was used to install Windows initially, but it can be one for the same version as the one of your Windows installation.
In most cases you get it from the official Microsoft sticker on your computer case, or from the official Microsoft sticker that came with your Windows CD if it has not been stuck to the case, or if you can't find that or don't have that, you can use a program to find the Product Key your Windows installation is presently using, BEFORE you run the Repair Setup (Repair install) - e.g. search for: keyfinder, by Jelly Bean whatever (it also finds other Microsoft software keys) - BUT you must be able to load Windows in order to run such a program.